EP4245736A1 - Optical glass, optical element, optical system, cemented lens, interchangable lens for camera, objective lens for microscope, and optical device - Google Patents

Optical glass, optical element, optical system, cemented lens, interchangable lens for camera, objective lens for microscope, and optical device Download PDF

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Publication number
EP4245736A1
EP4245736A1 EP20961572.3A EP20961572A EP4245736A1 EP 4245736 A1 EP4245736 A1 EP 4245736A1 EP 20961572 A EP20961572 A EP 20961572A EP 4245736 A1 EP4245736 A1 EP 4245736A1
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EP
European Patent Office
Prior art keywords
tio
content rate
bao
sio
optical
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Application number
EP20961572.3A
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German (de)
French (fr)
Inventor
Tetsuya Koide
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Nikon Corp
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Nikon Corp
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    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00Glass compositions
    • C03C3/12Silica-free oxide glass compositions
    • C03C3/16Silica-free oxide glass compositions containing phosphorus
    • C03C3/17Silica-free oxide glass compositions containing phosphorus containing aluminium or beryllium
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00Glass compositions
    • C03C3/12Silica-free oxide glass compositions
    • C03C3/16Silica-free oxide glass compositions containing phosphorus
    • C03C3/21Silica-free oxide glass compositions containing phosphorus containing titanium, zirconium, vanadium, tungsten or molybdenum
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00Glass compositions
    • C03C3/04Glass compositions containing silica
    • C03C3/062Glass compositions containing silica with less than 40% silica by weight
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00Glass compositions
    • C03C3/04Glass compositions containing silica
    • C03C3/062Glass compositions containing silica with less than 40% silica by weight
    • C03C3/064Glass compositions containing silica with less than 40% silica by weight containing boron
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00Glass compositions
    • C03C3/12Silica-free oxide glass compositions
    • C03C3/16Silica-free oxide glass compositions containing phosphorus
    • C03C3/19Silica-free oxide glass compositions containing phosphorus containing boron
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B13/00Optical objectives specially designed for the purposes specified below
    • G02B13/001Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras
    • G02B13/0055Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras employing a special optical element
    • G02B13/006Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras employing a special optical element at least one element being a compound optical element, e.g. cemented elements
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B21/00Microscopes
    • G02B21/02Objectives

Definitions

  • the present invention relates to an optical glass, an optical element, an optical system, a cemented lens, an optical system, an interchangeable camera lens, an objective lens for a microscope, and an optical device.
  • a first aspect according to the present invention is an optical glass including: by mass%, 20% to 55% of a content rate of P 2 O 5 ; 10% to 40% of a content rate of TiO 2 ; 0% to 30% of a content rate of Nb 2 O 5 ; 0% to 2% of a content rate of Al 2 O 3 ; 0% to 10% of a content rate of B 2 O 3 ; 0% to 30% of a content rate of BaO; 0% to 30% of a content rate of Bi 2 O 3 ; 0% to 20% of a content rate of Ta 2 O 5 ; and 0% to 25% of a content rate of WO 3 , wherein a ratio of a content rate of TiO 2 to a total content rate of P 2 O 5 , B 2 O 3 , and Al 2 O 3 (TiO 2 /(P 2 O 5 + B 2 O 3 + Al 2 O 3 )) is from 0.25 to 0.85, and a ratio of a content rate of TiO 2 to a total content rate of TiO 2
  • An optical glass includes: by mass%, 20% to 55% of a content rate of P 2 O 5 ; 10% to 40% of a content rate of TiO 2 ; 0% to 30% of a content rate of Nb 2 O 5 ; 0% to 2% of a content rate of Al 2 O 3 ; 0% to 10% of a content rate of B 2 O 3 ; 0% to 30% of a content rate of BaO; 0% to 30% of a content rate of Bi 2 O 3 ; 0% to 20% of a content rate of Ta 2 O 5 ; and 0% to 25% of a content rate of WO 3 , wherein a ratio of a total content rate of BaO and TiO 2 to a content rate of P 2 O 5 ((BaO + TiO 2 )/P 2 O 5 ) is from 0.40 to 1.50.
  • a second aspect according to the present invention is an optical element using the optical glass described above.
  • a third aspect according to the present invention is an optical system including the optical element described above.
  • a fourth aspect according to the present invention is an interchangeable camera lens including the optical system including the optical element described above.
  • a fifth aspect according to the present invention is an objective lens for a microscope including the optical system including the optical element described above.
  • a sixth aspect according to the present invention is an optical device including the optical system including the optical element described above.
  • a seventh aspect according to the present invention is a cemented lens including a first lens element and a second lens element, and at least one of the first lens element and the second lens element is the optical glass described above.
  • An eighth aspect according to the present invention is an optical system including the cemented lens described above.
  • a ninth aspect according to the present invention is an objective lens for a microscope including the optical system including the cemented lens described above.
  • a tenth aspect according to the present invention is an interchangeable camera lens including the optical system including the cemented lens described above.
  • An eleventh aspect according to the present invention is an optical device including the optical system including the cemented lens described above.
  • present embodiment description is made on an embodiment of the present invention (hereinafter, referred to as the "present embodiment").
  • the present embodiment described below is an example for describing the present invention, and is not intended to limit the present invention to the contents described below.
  • the present invention may be modified as appropriate and carried out without departing from the gist thereof.
  • a content rate of each of all the components is expressed with mass% (mass percentage) with respect to the total weight of glass in terms of an oxide-converted composition unless otherwise stated.
  • mass% mass percentage
  • the oxide-converted composition described herein is a composition in which each component contained in the glass is expressed with a total mass of the oxides as 100 mass%.
  • An expression that a Q content rate is "0% to N%" is an expression including a case where a Q component is not included and a case where a Q component is more than 0% and equal to or less than N%.
  • An expression that a "Q component is not included” means that the Q component is not substantially included, and that a content rate of the constituent component is an impurity level or less.
  • the impurity level or less means, for example, being less than 0.01%.
  • devitrification resistance stability means resistance to devitrification of glass.
  • devitrification means a phenomenon in which transparency of glass is lost due to crystallization, phase splitting, or the like that occurs when the glass is heated to a glass transition temperature or higher or when the glass is lowered from a molten state to a liquid phase temperature or lower.
  • An optical glass according to the present embodiment is an optical glass including: by mass%, 20% to 55% of a content rate of P 2 O 5 ; 10% to 40% of a content rate of TiO 2 ; 0% to 30% of a content rate of Nb 2 O 5 ; 0% to 2% of a content rate of Al 2 O 3 ; 0% to 10% of a content rate of B 2 O 3 ; 0% to 30% of a content rate of BaO; 0% to 30% of a content rate of Bi 2 O 3 ; 0% to 20% of a content rate of Ta 2 O 5 ; and 0% to 25% of a content rate of WO 3 , wherein a ratio of a content rate of TiO 2 to a total content rate of P 2 O 5 , B 2 O 3 , and Al 2 O 3 (TiO 2 /(P 2 O 5 + B 2 O 3 + Al 2 O 3 )) is from 0.25 to 0.85, and a ratio of a content rate of TiO 2 to a total content rate of TiO 2
  • An optical glass includes: by mass%, 20% to 55% of a content rate of P 2 O 5 ; 10% to 40% of a content rate of TiO 2 ; 0% to 30% of a content rate of Nb 2 O 5 ; 0% to 2% of a content rate of Al 2 O 3 ; 0% to 10% of a content rate of B 2 O 3 ; 0% to 30% of a content rate of BaO; 0% to 30% of a content rate of Bi 2 O 3 ; 0% to 20% of a content rate of Ta 2 O 5 ; and 0% to 25% of a content rate of WO 3 , wherein a ratio of a total content rate of BaO and TiO 2 to a content rate of P 2 O 5 ((BaO + TiO 2 )/P 2 O 5 ) is from 0.40 to 1.50.
  • the optical glass according to the present embodiment can have low dispersion (great abbe number) and can have a high partial dispersion ratio. Thus, a light-weighted lens that is advantageous in aberration correction can be achieved.
  • P 2 O 5 is a component that forms a glass frame, improves devitrification resistance stability, reduces a refractive index, and degrades chemical durability.
  • the content rate of P 2 O 5 is excessively reduced, devitrification is liable to be caused.
  • the content rate of P 2 O 5 is excessively increased, a refractive index is liable to be reduced, and chemical durability is liable to be degraded.
  • the content rate of P 2 O 5 is from 20% to 55%.
  • a lower limit of this content rate is preferably 25%, more preferably 30%, further preferably 38%.
  • An upper limit of this content rate is preferably 50%, more preferably 45%, further preferably 40%.
  • TiO 2 is a component that increases a refractive index and a partial dispersion ratio and reduces a transmittance.
  • a refractive index and a partial dispersion ratio are liable to be reduced.
  • a transmittance is liable to be degraded.
  • the content rate of TiO 2 is from 10% to 40%.
  • a lower limit of this content rate is preferably 15%, more preferably 17%.
  • An upper limit of this content rate is preferably 30%, more preferably 28%, further preferably 25%.
  • Nb 2 O 5 is a component that increases a refractive index, improves dispersion, and reduces a transmittance.
  • the content rate of Nb 2 O 5 is reduced, a refractive index is liable to be reduced.
  • the content rate of Nb 2 O 5 is increased, a transmittance is liable to be degraded.
  • the content rate of Nb 2 O 5 is from 0% to 30%.
  • a lower limit of this content rate is preferably more than 0%, more preferably 5% or more.
  • An upper limit of this content rate is preferably 25%, more preferably 18%, further preferably 10%.
  • Al 2 O 3 is a component that improves chemical durability and reduces a partial dispersion ratio and meltability.
  • the content rate of Al 2 O 3 is excessively reduced, chemical durability is liable to be degraded.
  • the content rate of Al 2 O 3 is excessively increased, a partial dispersion ratio is liable to be reduced, and meltability is liable to be degraded.
  • the content amount of Al 2 O 3 is from 0% to 2%.
  • a lower limit of this content rate is preferably 1%.
  • An upper limit of this content rate is preferably 1.6%.
  • the content rate of B 2 O 3 is from 0% to 10%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 6%, more preferably 4%.
  • BaO is a component that improves a partial dispersion ratio and degrade devitrification resistance stability.
  • the content rate of BaO is excessively reduced, a partial dispersion ratio is liable to be reduced.
  • the content rate of BaO is excessively increased, devitrification resistance stability is liable to be degraded.
  • the content rate of BaO is from 0% to 30%.
  • a lower limit of this content rate is preferably 3%, more preferably 5%, further preferably 7%.
  • An upper limit of this content rate is preferably 25%, more preferably 20%, further preferably 15%.
  • Bi 2 O 3 is a component that increases a refractive index and a partial dispersion ratio.
  • the content rate of Bi 2 O 3 is excessively increased, a transmittance is liable to be degraded, and dispersion is liable to be increased.
  • the content rate of Bi 2 O 3 is excessively reduced, meltability is liable to be degraded.
  • the content rate of Bi 2 O 3 is from 0% to 30%.
  • a lower limit of this content rate is preferably 2%, more preferably 5%, further preferably 10%.
  • An upper limit of this content rate is preferably 25%, more preferably 20%.
  • Ta 2 O 5 is a component that increases a refractive index, improves dispersion, and degrade devitrification resistance stability.
  • the content rate of Ta 2 O 5 is from 0% to 20%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 16%, more preferably 10%.
  • Ta is substantially excluded.
  • substantially excluded means that the component is not contained as a constituent component that affects a property of a glass composition beyond a concentration in which the component is inevitably contained as an impurity.
  • the component when the content amount is approximately 100 ppm, the component is considered to be substantially excluded.
  • the optical glass according to the present embodiment enables a content rate of Ta 2 O 5 being an expensive raw material to be reduced, and further enables such material to be excluded.
  • the optical glass according to the present embodiment is also excellent in reduction of raw material cost.
  • the content rate of WO 3 is from 0% to 25%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 20%, more preferably 15%, further preferably 10%.
  • a ratio of the content rate of TiO 2 to the total content rate of P 2 O 5 , B 2 O 3 , and Al 2 O 3 is preferably from 0.25 to 0.85.
  • a lower limit of this ratio is more preferably 0.30, further preferably 0.40.
  • An upper limit of this ratio is more preferably 0.70, further preferably 0.60.
  • a ratio of the content rate of TiO 2 to the total content rate of TiO 2 , Nb 2 O 5 , WO 3 , Bi 2 O 3 , and Ta 2 O 5 is preferably from 0.25 to 1.00.
  • a lower limit of this ratio is more preferably 0.30, further preferably 0.40.
  • An upper limit of this ratio is more preferably 0.90, further preferably 0.80.
  • a ratio of the total content rate of BaO and TiO 2 to the content rate of P 2 O 5 ((BaO + TiO 2 )/P 2 O 5 ) is preferably from 0.40 to 1.50.
  • a lower limit of this ratio is more preferably 0.70.
  • An upper limit of this ratio is more preferably 1.10, further preferably 0.90.
  • (BaO + TiO 2 )/P 2 O 5 falls within such range, a refractive index can be increased.
  • the optical glass according to the present embodiment may further contain, as any component, one or more compounds selected from the group consisting of Na 2 O, K 2 O, Li 2 O, ZnO, MgO, CaO, SrO, SiO 2 , ZrO 2 , Sb 2 O 3 , Y 2 O 3 , La 2 O 3 , and Gd 2 O 3 .
  • Na 2 O is a component that improves meltability and reduces a refractive index.
  • meltability is liable to be degraded.
  • content rate of Na 2 O is excessively increased, a refractive index is liable to be reduced, and chemical durability is liable to be degraded.
  • the content rate of Na 2 O is from 0% to 30%.
  • a lower limit of this content rate is preferably more than 0%, more preferably 5%.
  • An upper limit of this content rate is preferably 20%, more preferably 15%.
  • K 2 O is a component that improves meltability and reduces a refractive index.
  • meltability is liable to be degraded.
  • content rate of K 2 O is excessively increased, a refractive index is liable to be reduced, and chemical durability is liable to be degraded.
  • the content rate of K 2 O is from 0% to 25%.
  • a lower limit of this content rate is preferably more than 0%, more preferably 3%.
  • An upper limit of this content rate is preferably 20%, more preferably 15%, further preferably 5%.
  • the content rate of Li 2 O is from 0% to 5%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 4%, more preferably 2%.
  • ZnO is a component that improves devitrification resistance stability and reduces a partial dispersion ratio.
  • the content rate of ZnO is excessively reduced, devitrification resistance stability is liable to be degraded.
  • the content rate of ZnO is excessively increased, a partial dispersion ratio is liable to be reduced.
  • the content rate of ZnO is from 0% to 15%.
  • a lower limit of this content rate is preferably more than 0%, more preferably 1%.
  • An upper limit of this content rate is preferably 10%, more preferably 8%.
  • the content rate of MgO is from 0% to 10%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 5%, more preferably 4%.
  • the content rate of CaO is from 0% to 10%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 8%, more preferably 6%.
  • the content rate of SrO is from 0% to 15%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 12%, more preferably 10%.
  • the content rate of SiO 2 is from 0% to 5%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 3%, more preferably 1%.
  • the content rate of ZrO 2 is from 0% to 5%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 3% or less, more preferably 1.5%.
  • the content rate of Sb 2 O 3 is, from a viewpoint of a defoaming property at the time of melting of glass, from 0% to 1%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 0.5%, more preferably 0.2%.
  • the content rate of Y 2 O 3 is from 0% to 8%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 6%, more preferably 5%, further preferably 4.5%.
  • the content rate of La 2 O 3 is from 0% to 5%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 4%, more preferably 3.5%.
  • La 2 O 3 is more preferably substantially excluded.
  • substantially excluded means that the component is not contained as a constituent component that affects a property of a glass composition beyond a concentration in which the component is inevitably contained as an impurity. For example, when the content amount is approximately 100 ppm, the component is considered to be substantially excluded.
  • Gd 2 O 3 is an expensive raw material, and hence the content rate thereof is preferably from 0% to 10%.
  • a lower limit of this content rate may be more than 0%.
  • An upper limit of this content rate is preferably 8%, more preferably 7.5%.
  • optical glass according to the present embodiment preferably satisfies the following relationships.
  • a ratio of the content rate of TiO 2 to the content rate of P 2 O 5 is preferably from 0.25 to 0.85.
  • a lower limit of this ratio is more preferably 0.30, further preferably 0.40.
  • An upper limit of this ratio is more preferably 0.75, further preferably 0.60.
  • a ratio of the content rate of Al 2 O 5 to the content rate of TiO 2 is from 0 to 0.15.
  • a lower limit of this ratio may be more than 0.
  • An upper limit of this ratio is preferably 0.12, more preferably 0.09. When Al 2 O 3 /TiO 2 falls within such range, a partial dispersion ratio can be increased.
  • a ratio of the content rate of B 2 O 3 to the content rate of P 2 O 5 is preferably 0 to 0.30.
  • a lower limit of this ratio may be more than 0.
  • An upper limit of this ratio is more preferably 0.25, further preferably 0.20.
  • a ratio of the total content rate of BaO, TiO 2 , Nb 2 O 5 , WO 3 , Bi 2 O 3 , and Ta 2 O 5 to the total content rate of P 2 O 5 , B 2 O 3 , SiO 2 , and Al 2 O 3 ((BaO + TiO 2 + Nb 2 O 5 + WO 3 + Bi 2 O 3 + Ta 2 O 5 )/ (P 2 O 5 + B 2 O 3 + SiO 2 + Al 2 O 3 )) is preferably from 0.40 to 2.00.
  • a lower limit of this ratio is more preferably 0.50, further preferably 0.60.
  • An upper limit of this ratio is more preferably 1.60, further preferably 1.00.
  • a lower limit of this total content rate is preferably 7%, more preferably 9%, further preferably 11%.
  • An upper limit of this total content rate is preferably 25%, more preferably 20%, further preferably 18%.
  • a suitable combination of the content rates is the content rate of Li 2 O: 0% or more and 5% or less, the content rate of Na 2 O: 0% or more and 30% or less, and the content rate of K 2 O: 0% or more and 25% or less. With the combination, meltability can be increased, and degradation of chemical durability can be prevented.
  • a lower limit of this total content rate is preferably 5%, more preferably 8%, further preferably 10%.
  • An upper limit of this total content rate is preferably 25%, more preferably 15%.
  • Another suitable combination is the content rate of BaO: 0% or more and 30% or less, the content rate of ZnO: 0% or more and 15% or less, the content rate of MgO: 0% or more and 10% or less, the content rate of CaO: 0% or more and 10% or less, and the content rate of SrO: 0% or more and 15% or less.
  • a partial dispersion ratio can be increased, and low dispersion can be prevented.
  • the total content rate of SiO 2 and B 2 O 3 (SiO 2 + B 2 O 3 ) is from 0% to 10%.
  • a lower limit of this total content rate is preferably more than 0%, more preferably 1%, further preferably 2%.
  • An upper limit of this total content rate is preferably 7%, more preferably 6%, further preferably 4%.
  • Still another suitable combination is the content rate of SiO 2 : 0% or more and 5% or less and the content rate of B 2 O 3 : 0% or more and 10% or less. With the combination, meltability can be increased, and low dispersion can be prevented.
  • a lower limit of this ratio is more preferably 0.20, further preferably 0.30.
  • An upper limit of this ratio is more preferably 1.60, further preferably 1.30.
  • a lower limit of this ratio is preferably more than 0, more preferably 0.20, further preferably 0.80.
  • An upper limit of this ratio is more preferably 2.00, further preferably 1.50.
  • a known component such as a fining agent, a coloring agent, a defoaming agent, and a fluorine compound may be added by an appropriate amount to the glass composition as needed.
  • other components may be added as long as the effect of the optical glass according to the present embodiment can be exerted.
  • a method of manufacturing the optical glass according to the present embodiment is not particularly limited, and a publicly known method may be adopted. Further, suitable conditions can be selected for the manufacturing conditions as appropriate. For example, there may be adopted a manufacturing method in which raw materials such as oxides, carbonates, nitrates, and sulfates are blended to obtain a target composition, melted at a temperature of preferably from 1,100 to 1,400 degrees Celsius, uniformed by stirring, subjected to defoaming, then poured in a mold, and molded.
  • a lower limit of the melting temperature described above is more preferably 1200 degrees Celsius.
  • An upper limit of the melting temperature is more preferably 1350 degrees Celsius, further preferably 1300 degrees Celsius.
  • the optical glass thus obtained is processed to have a desired shape by performing reheat pressing or the like as needed, and is subjected to polishing. With this, a desired optical element is obtained.
  • a high-purity material with a small content rate of impurities is preferably used as the raw material.
  • the high-purity material indicates a material including 99.85 mass% or more of a concerned component.
  • the optical glass according to the present embodiment preferably has a high refractive index (a refractive index (n d ) is large).
  • a refractive index (n d ) is large.
  • the refractive index (n d ) of the optical glass according to the present embodiment with respect to a d-line preferably falls within a range from 1.60 to 1.85.
  • a lower limit of the refractive index (n d ) is more preferably 1.65.
  • An upper limit of the refractive index (n d ) is more preferably 1.80.
  • An abbe number (v d ) of the optical glass according to the present embodiment preferably falls within a range from 20 to 35.
  • a lower limit of the abbe number ( ⁇ d ) is more preferably 22.
  • An upper limit of the abbe number (v d ) is more preferably 30.
  • the optical glass according to the present embodiment preferably has a large partial dispersion ratio (P g , F ).
  • the partial dispersion ratio (P g , F ) of the optical glass according to the present embodiment is preferably 0.61 or more.
  • a lower limit of the partial dispersion ratio (P g , F ) is more preferably 0.62, further preferably 0.64.
  • An upper limit of the partial dispersion ratio (P g , F ) is not particularly limited, but may be, for example, 0.66.
  • the optical glass according to the present embodiment preferably has great abnormal dispersibility ( ⁇ P g , F ).
  • the value ( ⁇ P g , F ) indicating the abnormal dispersibility of the optical glass according to the present embodiment is preferably 0.015 or more.
  • a lower limit of the value ( ⁇ P g , F ) indicating the abnormal dispersibility is more preferably 0.020, further preferably 0.030.
  • An upper limit of the value ( ⁇ P g , F ) indicating the abnormal dispersibility is not particularly limited, but may be, for example, 0.055.
  • the optical glass according to the present embodiment can be suitably used as, for example, an optical element included in optical equipment.
  • an optical element includes a mirror, a lens, a prism, a filter, and the like.
  • Examples of an optical system in which the optical element described above is used include, for example, an objective lens, a condensing lens, an image forming lens, and an interchangeable camera lens.
  • the optical system can be suitably used for an imaging device, such as a camera with an interchangeable lens and a camera with a non-interchangeable lens, and various optical devices such as a microscope device such as a fluorescence microscope and a multi-photon microscope.
  • the optical device is not limited to the imaging device and the microscope described above, and also includes a telescope, a binocular, a laser range finder, a projector, and the like, which are not limited thereto. An example thereof will be described below.
  • FIG. 1 is a perspective view illustrating one example of an optical device according to the present embodiment as an imaging device.
  • An imaging device 1 is a so-called digital single-lens reflex camera (a lens-interchangeable camera), and a photographing lens 103 (an optical system) includes, as a base material, an optical element including the optical glass according to the present embodiment.
  • a lens barrel 102 is mounted to a lens mount (not illustrated) of a camera body 101 in a removable manner.
  • An image is formed with light, which passes through the lens 103 of the lens barrel 102, on a sensor chip (solid-state imaging elements) 104 of a multi-chip module 106 arranged on a back surface side of the camera body 101.
  • the sensor chip 104 is a so-called bare chip such as a CMOS image sensor, and the multi-chip module 106 is, for example, a Chip On Glass (COG) type module including the sensor chip 104 being a bare chip mounted on a glass substrate 105.
  • COG Chip On Glass
  • FIGS. 2 and 3 are schematic diagrams illustrating another example of the optical device according to the present embodiment as an imaging device.
  • FIG. 2 illustrates a front view of an imaging device CAM
  • FIG. 3 illustrates a back view of the imaging device CAM.
  • the imaging device CAM is a so-called digital still camera (a fixed lens camera), and a photographing lens WL (an optical system) includes an optical element including the optical glass according to the present embodiment, as a base material.
  • a shutter (not illustrated) of the photographing lens WL is opened, light from an object to be imaged (a body) is converged by the photographing lens WL and forms an image on imaging elements arranged on an image surface.
  • An object image formed on the imaging elements is displayed on a liquid crystal monitor M arranged on the back of the imaging device CAM.
  • a photographer decides composition of the object image while viewing the liquid crystal monitor M, then presses down a release button B1 to capture the object image with the imaging elements.
  • the object image is recorded and stored in a memory (not illustrated).
  • An auxiliary light emitting unit EF that emits auxiliary light in a case that the object is dark and a function button B2 to be used for setting various conditions of the imaging device CAM and the like are arranged on the imaging device CAM.
  • the optical glass according to the present embodiment is suitable as a member of such optical equipment.
  • examples of the optical equipment to which the present embodiment is applicable include a projector and the like.
  • examples of the optical element include a prism and the like.
  • FIG. 4 is a block diagram illustrating an example of a configuration of a multi-photon microscope 2 according to the present embodiment.
  • the multi-photon microscope 2 includes an objective lens 206, a condensing lens 208, and an image forming lens 210.
  • At least one of the objective lens 206, the condensing lens 208, and the image forming lens 210 includes an optical element including, as a base material, the optical glass according to the present embodiment.
  • description is mainly made on the optical system of the multi-photon microscope 2.
  • a pulse laser device 201 emits ultrashort pulse light having, for example, a near infrared wavelength (approximately 1,000 nm) and a pulse width of a femtosecond unit (for example, 100 femtoseconds).
  • ultrashort pulse light immediately after being emitted from the pulse laser device 201 is linearly polarized light that is polarized in a predetermined direction.
  • a pulse division device 202 divides the ultrashort pulse light, increases a repetition frequency of the ultrashort pulse light, and emits the ultrashort pulse light.
  • a beam adjustment unit 203 has a function of adjusting a beam diameter of the ultrashort pulse light, which enters from the pulse division device 202, to a pupil diameter of the objective lens 206, a function of adjusting convergence and divergence angles of the ultrashort pulse light in order to correct chromatic aberration (a focus difference) on an axis of a wavelength of light emitted from a sample S and the wavelength of the ultrashort pulse light, a pre-chirp function (group velocity dispersion compensation function) providing inverse group velocity dispersion to the ultrashort pulse light in order to correct the pulse width of the ultrashort pulse light, which is increased due to group velocity dispersion at the time of passing through the optical system, and the like.
  • the ultrashort pulse light emitted from the pulse laser device 201 have a repetition frequency increased by the pulse division device 202, and is subjected to the above-mentioned adjustments by the beam adjustment unit 203.
  • the ultrashort pulse light emitted from the beam adjustment unit 203 is reflected on a dichroic mirror 204 in a direction toward a dichroic mirror, passes through the dichroic mirror 205, is converged by the objective lens 206, and is radiated to the sample S.
  • an observation surface of the sample S may be scanned with the ultrashort pulse light through use of scanning means (not illustrated).
  • a fluorescent pigment by which the sample S is dyed is subjected to multi-photon excitation in an irradiated region with the ultrashort pulse light and the vicinity thereof on the sample S, and fluorescence having a wavelength shorter than a near infrared wavelength of the ultrashort pulse light (hereinafter, also referred to "observation light”) is emitted.
  • the observation light emitted from the sample S in a direction toward the objective lens 206 is collimated by the objective lens 206, and is reflected on the dichroic mirror 205 or passes through the dichroic mirror 205 depending on the wavelength.
  • the observation light reflected on the dichroic mirror 205 enters a fluorescence detection unit 207.
  • the fluorescence detection unit 207 is formed of a barrier filter, a photo multiplier tube (PMT), or the like, receives the observation light reflected on the dichroic mirror 205, and outputs an electronic signal depending on an amount of the light.
  • the fluorescence detection unit 207 detects the observation light over the observation surface of the sample S, in conformity with the ultrashort pulse light scanning on the observation surface of the sample S.
  • all the observation light emitted from the sample S in a direction toward the objective lens 206 may be detected by the fluorescence detection unit 211 by excluding the dichroic mirror 205 from the optical path.
  • the observation light is de-scanned by a scanning means (not illustrated), passes through the dichroic mirror 204, is converged by the condensing lens 208, passes through a pinhole 209 provided at a position substantially conjugate to a focal position of the objective lens 206, passes through the image forming lens 210, and enters a fluorescence detection unit 211.
  • the fluorescence detection unit 211 is formed of a barrier filter, a PMT, or the like, receives the observation light forming an image on a light formed by the image forming lens 210 reception surface of the fluorescence detection unit 211, and outputs an electronic signal depending on an amount of the light.
  • the fluorescence detection unit 211 detects the observation light over the observation surface of the sample S, in conformity with the ultrashort pulse light scanning on the observation surface of the sample S.
  • the observation light emitted from the sample S in a direction opposite to the objective lens 206 is reflected on a dichroic mirror 212, and enters a fluorescence detection unit 213.
  • the fluorescence detection unit 113 is formed of, for example, a barrier filter, a PMT, or the like, receives the observation light reflected on the dichroic mirror 212, and outputs an electronic signal depending on an amount of the light.
  • the fluorescence detection unit 213 detects the observation light over the observation surface of the sample S, in conformity with the ultrashort pulse light scanning on the observation surface of the sample S.
  • the electronic signals output from the fluorescence detection units 207, 211, and 213 are input to, for example, a computer (not illustrated).
  • the computer is capable of generating an observation image, displaying the generated observation image, storing data on the observation image, based on the input electronic signals.
  • FIG. 5 is a schematic diagram illustrating one example of a cemented lens according to the present embodiment.
  • a cemented lens 3 is a compound lens including a first lens element 301 and a second lens element 302.
  • the optical glass according to the present embodiment is used as at least one of the first lens element and the second lens element.
  • the first lens element and the second lens element are joined through intermediation with a joining member 303.
  • a joining member 303 a publicly known adhesive agent or the like may be used.
  • the "lens element” refers to each lens constituting a single lens or a cemented lens.
  • the cemented lens according to the present embodiment is effective in view of correction of chromatic aberration, and can be used suitably for the optical element, the optical system, and the optical device that are described above and the like. Furthermore, the optical system including the cemented lens can be used suitably for, especially, an interchangeable camera lens and an optical device. Note that, in the aspect described above, description is made on the cemented lens using the two lens elements.
  • the present invention is however not limited thereto, and a cemented lens using three or more lens elements may be used. When the cemented lens uses three or more lens elements, it is only required that at least one of the three or more lens elements be formed by using the optical glass according to the present embodiment.
  • the optical glasses in each example and each comparative example were produced by the following procedures. First, glass raw materials selected from oxides, hydroxides, phosphate compounds (phosphates, orthophosphoric acids, and the like), carbonates, nitrates, and the like were weighed so as to obtain the compositions (mass%) illustrated in each table. Next, the weighed raw materials were mixed and put in a platinum crucible, melted at a temperature of from 1,100 to 1,350 degrees Celsius, and uniformed by stirring. After defoaming, the resultant was lowered to an appropriate temperature, poured in a mold, annealed, and molded. In this manner, each sample was obtained.
  • FIG. 6 is a graph in which P g,F and ⁇ d of Examples and Comparative Examples are plotted.
  • n d refractive index
  • v d abbe number
  • the partial dispersion ratio (P g , F ) in each of the samples indicates a ratio of partial dispersion (n g - n F ) to main dispersion (n F - nc), and was obtained based on Expression (2) given below.
  • n g indicates a refractive index of the glass with respect to light having a wavelength of 435.835 nm.
  • a value of the partial dispersion ratio (P g , F ) was truncated to the third decimal place.
  • P g , F n g ⁇ n F / n F ⁇ n C
  • the abnormal dispersibility ( ⁇ P g , F ) of each sample indicates a deviation from a partial dispersion ratio standard line with reference to two types of glass of F2 and K7 as glass having normal dispersion.
  • a difference in ordinate between a straight line connecting two types of glass and a value of glass to be compared is a deviation of the partial dispersion ratio, i.e., abnormal dispersibility ( ⁇ P g , F ).
  • Tables 1 to 36 illustrate a composition of components by mass% in terms of an oxide and evaluation results of physical properties for optical glass of Examples and Comparative Examples.
  • the optical glass could not be obtained, and thus physical properties were "unmeasurable”.
  • optical glasses in Examples were highly dispersive and had a high partial dispersion ratio. Further, it was confirmed that the optical glasses in Examples were excellent in transparency with suppressed coloration.

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Abstract

An optical glass includes: by mass%, 20% to 55% of a content rate of P2O5; 10% to 40% of a content rate of TiO2; 0% to 30% of a content rate of Nb2O5; 0% to 2% of a content rate of Al2O3; 0% to 10% of a content rate of B2O3; 0% to 30% of a content rate of BaO; 0% to 30% of a content rate of Bi2O3; 0% to 20% of a content rate of Ta2O5; and 0% to 25% of a content rate of WO3, wherein a ratio of a content rate of TiO2 to a total content rate of P2O5, B2O3, and Al2O3 (TiO2/(P2O5 + B2O3 + Al2O3)) is from 0.25 to 0.85, and a ratio of a content rate of TiO2 to a total content rate of TiO2, Nb2O5, WO3, Bi2O3, and Ta2O5 (TiO2/(TiO2 + Nb2O5 + WO3 + Bi2O3 + Ta2O5)) is from 0.25 to 1.00.

Description

    Technical Field
  • The present invention relates to an optical glass, an optical element, an optical system, a cemented lens, an optical system, an interchangeable camera lens, an objective lens for a microscope, and an optical device.
  • Background Art
  • In recent years, imaging equipment and the like including an image sensor with a large number of pixels have been developed, and an optical glass that has low dispersion and a high partial dispersion ratio has been demanded as an optical glass to be used for such equipment.
  • Citation List Patent Literature
  • PTL 1: JP 2006-219365 A
  • Summary of Invention
  • A first aspect according to the present invention is an optical glass including: by mass%, 20% to 55% of a content rate of P2O5; 10% to 40% of a content rate of TiO2; 0% to 30% of a content rate of Nb2O5; 0% to 2% of a content rate of Al2O3; 0% to 10% of a content rate of B2O3; 0% to 30% of a content rate of BaO; 0% to 30% of a content rate of Bi2O3; 0% to 20% of a content rate of Ta2O5; and 0% to 25% of a content rate of WO3, wherein a ratio of a content rate of TiO2 to a total content rate of P2O5, B2O3, and Al2O3 (TiO2/(P2O5 + B2O3 + Al2O3)) is from 0.25 to 0.85, and a ratio of a content rate of TiO2 to a total content rate of TiO2, Nb2O5, WO3, Bi2O3, and Ta2O5 (TiO2/(TiO2 + Nb2O5 + WO3 + Bi2O3 + Ta2O5)) is from 0.25 to 1.00. An optical glass includes: by mass%, 20% to 55% of a content rate of P2O5; 10% to 40% of a content rate of TiO2; 0% to 30% of a content rate of Nb2O5; 0% to 2% of a content rate of Al2O3; 0% to 10% of a content rate of B2O3; 0% to 30% of a content rate of BaO; 0% to 30% of a content rate of Bi2O3; 0% to 20% of a content rate of Ta2O5; and 0% to 25% of a content rate of WO3, wherein a ratio of a total content rate of BaO and TiO2 to a content rate of P2O5 ((BaO + TiO2)/P2O5) is from 0.40 to 1.50.
  • A second aspect according to the present invention is an optical element using the optical glass described above.
  • A third aspect according to the present invention is an optical system including the optical element described above.
  • A fourth aspect according to the present invention is an interchangeable camera lens including the optical system including the optical element described above.
  • A fifth aspect according to the present invention is an objective lens for a microscope including the optical system including the optical element described above.
  • A sixth aspect according to the present invention is an optical device including the optical system including the optical element described above.
  • A seventh aspect according to the present invention is a cemented lens including a first lens element and a second lens element, and at least one of the first lens element and the second lens element is the optical glass described above.
  • An eighth aspect according to the present invention is an optical system including the cemented lens described above.
  • A ninth aspect according to the present invention is an objective lens for a microscope including the optical system including the cemented lens described above.
  • A tenth aspect according to the present invention is an interchangeable camera lens including the optical system including the cemented lens described above.
  • An eleventh aspect according to the present invention is an optical device including the optical system including the cemented lens described above.
  • Brief Description of Drawings
    • FIG. 1 is a perspective view illustrating one example of an optical device according to the present embodiment as an imaging device.
    • FIG. 2 is a schematic diagram illustrating another example of the optical device according to the present embodiment as an imaging device, and is a front view of the imaging device.
    • FIG. 3 is a schematic diagram illustrating another example of the optical device according to the present embodiment as an imaging device, and is a back view of the imaging device.
    • FIG. 4 is a block diagram illustrating one example of a configuration of a multi-photon microscope according to the present embodiment.
    • FIG. 5 is a schematic diagram illustrating one example of a cemented lens according to the present embodiment.
    • FIG. 6 is a graph in which Pg,F and νd of Examples and Comparative Examples are plotted.
    Description of Embodiments
  • Hereinafter, description is made on an embodiment of the present invention (hereinafter, referred to as the "present embodiment"). The present embodiment described below is an example for describing the present invention, and is not intended to limit the present invention to the contents described below. The present invention may be modified as appropriate and carried out without departing from the gist thereof.
  • In the present specification, a content rate of each of all the components is expressed with mass% (mass percentage) with respect to the total weight of glass in terms of an oxide-converted composition unless otherwise stated. Note that, assuming that oxides, complex salt, and the like, which are used as raw materials as glass constituent components in the present embodiment, are all decomposed and turned into oxides at the time of melting, the oxide-converted composition described herein is a composition in which each component contained in the glass is expressed with a total mass of the oxides as 100 mass%.
  • An expression that a Q content rate is "0% to N%" is an expression including a case where a Q component is not included and a case where a Q component is more than 0% and equal to or less than N%.
  • An expression that a "Q component is not included" means that the Q component is not substantially included, and that a content rate of the constituent component is an impurity level or less. The impurity level or less means, for example, being less than 0.01%.
  • An expression of "devitrification resistance stability" means resistance to devitrification of glass. Here, "devitrification" means a phenomenon in which transparency of glass is lost due to crystallization, phase splitting, or the like that occurs when the glass is heated to a glass transition temperature or higher or when the glass is lowered from a molten state to a liquid phase temperature or lower.
  • An optical glass according to the present embodiment is an optical glass including: by mass%, 20% to 55% of a content rate of P2O5; 10% to 40% of a content rate of TiO2; 0% to 30% of a content rate of Nb2O5; 0% to 2% of a content rate of Al2O3; 0% to 10% of a content rate of B2O3; 0% to 30% of a content rate of BaO; 0% to 30% of a content rate of Bi2O3; 0% to 20% of a content rate of Ta2O5; and 0% to 25% of a content rate of WO3, wherein a ratio of a content rate of TiO2 to a total content rate of P2O5, B2O3, and Al2O3 (TiO2/(P2O5 + B2O3 + Al2O3)) is from 0.25 to 0.85, and a ratio of a content rate of TiO2 to a total content rate of TiO2, Nb2O5, WO3, Bi2O3, and Ta2O5 (TiO2/(TiO2 + Nb2O5 + WO3 + Bi2O3 + Ta2O5)) is from 0.25 to 1.00. An optical glass includes: by mass%, 20% to 55% of a content rate of P2O5; 10% to 40% of a content rate of TiO2; 0% to 30% of a content rate of Nb2O5; 0% to 2% of a content rate of Al2O3; 0% to 10% of a content rate of B2O3; 0% to 30% of a content rate of BaO; 0% to 30% of a content rate of Bi2O3; 0% to 20% of a content rate of Ta2O5; and 0% to 25% of a content rate of WO3, wherein a ratio of a total content rate of BaO and TiO2 to a content rate of P2O5 ((BaO + TiO2)/P2O5) is from 0.40 to 1.50.
  • The optical glass according to the present embodiment can have low dispersion (great abbe number) and can have a high partial dispersion ratio. Thus, a light-weighted lens that is advantageous in aberration correction can be achieved.
  • P2O5 is a component that forms a glass frame, improves devitrification resistance stability, reduces a refractive index, and degrades chemical durability. When the content rate of P2O5 is excessively reduced, devitrification is liable to be caused. When the content rate of P2O5 is excessively increased, a refractive index is liable to be reduced, and chemical durability is liable to be degraded. From such a viewpoint, the content rate of P2O5 is from 20% to 55%. A lower limit of this content rate is preferably 25%, more preferably 30%, further preferably 38%. An upper limit of this content rate is preferably 50%, more preferably 45%, further preferably 40%. When the content rate of P2O5 falls within such a range, devitrification resistance stability can be improved, chemical durability can be satisfactory, and a refractive index can be increased.
  • TiO2 is a component that increases a refractive index and a partial dispersion ratio and reduces a transmittance. When the content rate of TiO2 is excessively reduced, a refractive index and a partial dispersion ratio are liable to be reduced. When the content rate of TiO2 is excessively increased, a transmittance is liable to be degraded. From such a viewpoint, the content rate of TiO2 is from 10% to 40%. A lower limit of this content rate is preferably 15%, more preferably 17%. An upper limit of this content rate is preferably 30%, more preferably 28%, further preferably 25%. When the content rate of TiO2 falls within such range, a high transmittance can be achieved without reducing a refractive index and a partial dispersion ratio.
  • Nb2O5 is a component that increases a refractive index, improves dispersion, and reduces a transmittance. When the content rate of Nb2O5 is reduced, a refractive index is liable to be reduced. When the content rate of Nb2O5 is increased, a transmittance is liable to be degraded. From such a viewpoint, the content rate of Nb2O5 is from 0% to 30%. A lower limit of this content rate is preferably more than 0%, more preferably 5% or more. An upper limit of this content rate is preferably 25%, more preferably 18%, further preferably 10%.
  • Al2O3 is a component that improves chemical durability and reduces a partial dispersion ratio and meltability. When the content rate of Al2O3 is excessively reduced, chemical durability is liable to be degraded. When the content rate of Al2O3 is excessively increased, a partial dispersion ratio is liable to be reduced, and meltability is liable to be degraded. From such a viewpoint, the content amount of Al2O3 is from 0% to 2%. A lower limit of this content rate is preferably 1%. An upper limit of this content rate is preferably 1.6%. When the content rate of Al2O3 falls within such range, chemical durability can be increased, and reduction of a partial dispersion ratio can be prevented.
  • From a viewpoint of achieving high dispersion, the content rate of B2O3 is from 0% to 10%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 6%, more preferably 4%.
  • BaO is a component that improves a partial dispersion ratio and degrade devitrification resistance stability. When the content rate of BaO is excessively reduced, a partial dispersion ratio is liable to be reduced. When the content rate of BaO is excessively increased, devitrification resistance stability is liable to be degraded. From such a viewpoint, the content rate of BaO is from 0% to 30%. A lower limit of this content rate is preferably 3%, more preferably 5%, further preferably 7%. An upper limit of this content rate is preferably 25%, more preferably 20%, further preferably 15%. When the content rate of BaO falls within such range, a partial dispersion ratio can be increased, and degradation of devitrification resistance stability can be prevented.
  • Bi2O3 is a component that increases a refractive index and a partial dispersion ratio. When the content rate of Bi2O3 is excessively increased, a transmittance is liable to be degraded, and dispersion is liable to be increased. When the content rate of Bi2O3 is excessively reduced, meltability is liable to be degraded. From such a viewpoint, the content rate of Bi2O3 is from 0% to 30%. A lower limit of this content rate is preferably 2%, more preferably 5%, further preferably 10%. An upper limit of this content rate is preferably 25%, more preferably 20%. When the content rate of Bi2O3 falls within such range, meltability can be increased, and a dispersion increase can be prevented.
  • Ta2O5 is a component that increases a refractive index, improves dispersion, and degrade devitrification resistance stability. When the content rate of Ta2O5 is increased, devitrification resistance stability is liable to be degraded. From such a viewpoint, the content rate of Ta2O5 is from 0% to 20%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 16%, more preferably 10%. Further preferably, Ta is substantially excluded. Here, "substantially excluded" means that the component is not contained as a constituent component that affects a property of a glass composition beyond a concentration in which the component is inevitably contained as an impurity. For example, when the content amount is approximately 100 ppm, the component is considered to be substantially excluded. The optical glass according to the present embodiment enables a content rate of Ta2O5 being an expensive raw material to be reduced, and further enables such material to be excluded. Thus, the optical glass according to the present embodiment is also excellent in reduction of raw material cost.
  • From a viewpoint of a transmittance, the content rate of WO3 is from 0% to 25%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 20%, more preferably 15%, further preferably 10%.
  • A ratio of the content rate of TiO2 to the total content rate of P2O5, B2O3, and Al2O3 (TiO2/(P2O5 + B2O3 + Al2O3)) is preferably from 0.25 to 0.85. A lower limit of this ratio is more preferably 0.30, further preferably 0.40. An upper limit of this ratio is more preferably 0.70, further preferably 0.60. When TiO2/(P2O5 + B2O3 + Al2O3) falls within such range, a partial dispersion ratio can be increased.
  • A ratio of the content rate of TiO2 to the total content rate of TiO2, Nb2O5, WO3, Bi2O3, and Ta2O5 (TiO2/(TiO2 + Nb2O5 + WO3 + Bi2O3 + Ta2O5)) is preferably from 0.25 to 1.00. A lower limit of this ratio is more preferably 0.30, further preferably 0.40. An upper limit of this ratio is more preferably 0.90, further preferably 0.80. When TiO2/(TiO2 + Nb2O5 + WO3 + Bi2O3 + Ta2O5) falls within such range, a partial dispersion ratio can be increased.
  • A ratio of the total content rate of BaO and TiO2 to the content rate of P2O5 ((BaO + TiO2)/P2O5) is preferably from 0.40 to 1.50. A lower limit of this ratio is more preferably 0.70. An upper limit of this ratio is more preferably 1.10, further preferably 0.90. When (BaO + TiO2)/P2O5 falls within such range, a refractive index can be increased.
  • The optical glass according to the present embodiment may further contain, as any component, one or more compounds selected from the group consisting of Na2O, K2O, Li2O, ZnO, MgO, CaO, SrO, SiO2, ZrO2, Sb2O3, Y2O3, La2O3, and Gd2O3.
  • Na2O is a component that improves meltability and reduces a refractive index. When the content rate of Na2O is excessively reduced, meltability is liable to be degraded. When the content rate of Na2O is excessively increased, a refractive index is liable to be reduced, and chemical durability is liable to be degraded. From such a viewpoint, the content rate of Na2O is from 0% to 30%. A lower limit of this content rate is preferably more than 0%, more preferably 5%. An upper limit of this content rate is preferably 20%, more preferably 15%. When the content rate of Na2O falls within such range, meltability can be increased, and reduction of a refractive index and degradation of chemical durability can be prevented.
  • K2O is a component that improves meltability and reduces a refractive index. When the content rate of K2O is excessively reduced, meltability is liable to be degraded. When the content rate of K2O is excessively increased, a refractive index is liable to be reduced, and chemical durability is liable to be degraded. From such a viewpoint, the content rate of K2O is from 0% to 25%. A lower limit of this content rate is preferably more than 0%, more preferably 3%. An upper limit of this content rate is preferably 20%, more preferably 15%, further preferably 5%. When the content rate of K2O falls within such range, meltability can be increased, and reduction of a refractive index and degradation of chemical durability can be prevented.
  • From a viewpoint of meltability, the content rate of Li2O is from 0% to 5%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 4%, more preferably 2%.
  • ZnO is a component that improves devitrification resistance stability and reduces a partial dispersion ratio. When the content rate of ZnO is excessively reduced, devitrification resistance stability is liable to be degraded. When the content rate of ZnO is excessively increased, a partial dispersion ratio is liable to be reduced. From such a viewpoint, the content rate of ZnO is from 0% to 15%. A lower limit of this content rate is preferably more than 0%, more preferably 1%. An upper limit of this content rate is preferably 10%, more preferably 8%. When the content rate of ZnO falls within such range, devitrification resistance stability can be increased, and reduction of a partial dispersion ratio can be prevented.
  • From a viewpoint of achieving high dispersion, the content rate of MgO is from 0% to 10%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 5%, more preferably 4%.
  • From a viewpoint of achieving high dispersion, the content rate of CaO is from 0% to 10%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 8%, more preferably 6%.
  • From a viewpoint of achieving high dispersion, the content rate of SrO is from 0% to 15%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 12%, more preferably 10%.
  • From a viewpoint of meltability, the content rate of SiO2 is from 0% to 5%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 3%, more preferably 1%.
  • From a viewpoint of meltability, the content rate of ZrO2 is from 0% to 5%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 3% or less, more preferably 1.5%.
  • The content rate of Sb2O3 is, from a viewpoint of a defoaming property at the time of melting of glass, from 0% to 1%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 0.5%, more preferably 0.2%.
  • From a viewpoint of meltability, the content rate of Y2O3 is from 0% to 8%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 6%, more preferably 5%, further preferably 4.5%.
  • From a viewpoint of meltability, the content rate of La2O3 is from 0% to 5%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 4%, more preferably 3.5%. From a viewpoint of cost, La2O3 is more preferably substantially excluded. Here, "substantially excluded" means that the component is not contained as a constituent component that affects a property of a glass composition beyond a concentration in which the component is inevitably contained as an impurity. For example, when the content amount is approximately 100 ppm, the component is considered to be substantially excluded.
  • Gd2O3 is an expensive raw material, and hence the content rate thereof is preferably from 0% to 10%. A lower limit of this content rate may be more than 0%. An upper limit of this content rate is preferably 8%, more preferably 7.5%.
  • Furthermore, the optical glass according to the present embodiment preferably satisfies the following relationships.
  • A ratio of the content rate of TiO2 to the content rate of P2O5 (TiO2/P2O5) is preferably from 0.25 to 0.85. A lower limit of this ratio is more preferably 0.30, further preferably 0.40. An upper limit of this ratio is more preferably 0.75, further preferably 0.60. When TiO2/P2O5 falls within such range, a partial dispersion ratio can be increased.
  • A ratio of the content rate of Al2O5 to the content rate of TiO2 (Al2O3/TiO2) is from 0 to 0.15. A lower limit of this ratio may be more than 0. An upper limit of this ratio is preferably 0.12, more preferably 0.09. When Al2O3/TiO2 falls within such range, a partial dispersion ratio can be increased.
  • A ratio of the content rate of B2O3 to the content rate of P2O5 (B2O3/P2O5) is preferably 0 to 0.30. A lower limit of this ratio may be more than 0. An upper limit of this ratio is more preferably 0.25, further preferably 0.20. When B2O3/P2O5 falls within such range, a partial dispersion ratio can be increased.
  • A ratio of the total content rate of BaO, TiO2, Nb2O5, WO3, Bi2O3, and Ta2O5 to the total content rate of P2O5, B2O3, SiO2, and Al2O3 ((BaO + TiO2 + Nb2O5 + WO3 + Bi2O3 + Ta2O5)/ (P2O5 + B2O3 + SiO2 + Al2O3)) is preferably from 0.40 to 2.00. A lower limit of this ratio is more preferably 0.50, further preferably 0.60. An upper limit of this ratio is more preferably 1.60, further preferably 1.00. When (BaO + TiO2 + Nb2O5 + WO3 + Bi2O3 + Ta2O5) / (P2O5 + B2O3 + SiO2 + Al2O3) falls within such a range, a partial dispersion ratio can be increased, and reduction of a refractive index can be prevented.
  • From a viewpoint of meltability, a refractive index, and chemical durability, the total content rate of Li2O, Na2O, and K2O (ΣA2O; where, A = Li, Na, K) is 5% to 35%. A lower limit of this total content rate is preferably 7%, more preferably 9%, further preferably 11%. An upper limit of this total content rate is preferably 25%, more preferably 20%, further preferably 18%.
  • A suitable combination of the content rates is the content rate of Li2O: 0% or more and 5% or less, the content rate of Na2O: 0% or more and 30% or less, and the content rate of K2O: 0% or more and 25% or less. With the combination, meltability can be increased, and degradation of chemical durability can be prevented.
  • From a viewpoint of meltability, a refractive index, and chemical durability, the total content rate of MgO, CaO, SrO, BaO, and ZnO (ZEO; where, E = Mg, Ca, Sr, Ba, Zn) is 0% to 30%. A lower limit of this total content rate is preferably 5%, more preferably 8%, further preferably 10%. An upper limit of this total content rate is preferably 25%, more preferably 15%.
  • Another suitable combination is the content rate of BaO: 0% or more and 30% or less, the content rate of ZnO: 0% or more and 15% or less, the content rate of MgO: 0% or more and 10% or less, the content rate of CaO: 0% or more and 10% or less, and the content rate of SrO: 0% or more and 15% or less. With the combination, a partial dispersion ratio can be increased, and low dispersion can be prevented.
  • The total content rate of SiO2 and B2O3 (SiO2 + B2O3) is from 0% to 10%. A lower limit of this total content rate is preferably more than 0%, more preferably 1%, further preferably 2%. An upper limit of this total content rate is preferably 7%, more preferably 6%, further preferably 4%.
  • Still another suitable combination is the content rate of SiO2: 0% or more and 5% or less and the content rate of B2O3: 0% or more and 10% or less. With the combination, meltability can be increased, and low dispersion can be prevented.
  • A ratio of the total content rate of Li2O, Na2O, and K2O (ΣA2O; where, A = Li, Na, K) to TiO2 (ΣA2O/TiO2) is preferably from 0.10 to 2.00. A lower limit of this ratio is more preferably 0.20, further preferably 0.30. An upper limit of this ratio is more preferably 1.60, further preferably 1.30. When ΣA2O/TiO2 falls within such range, a partial dispersion ratio can be increased, and reduction of meltability can be prevented.
  • A ratio of the total content rate of Li2O, Na2O, and K2O (ΣA2O; where, A = Li, Na, K) to the total content rate of MgO, CaO, SrO, BaO, and ZnO (ZEO; where, E = Mg, Ca, Sr, Ba, Zn) (ΣEO/ΣA2O) is preferably from 0 to 3.00. A lower limit of this ratio is preferably more than 0, more preferably 0.20, further preferably 0.80. An upper limit of this ratio is more preferably 2.00, further preferably 1.50. When ΣEO/ΣA2O falls within such range, meltability can be increased, and reduction of a refractive index can be prevented.
  • For the purpose of, for example, performing fine adjustments of fining, coloration, decoloration, and optical constant values, a known component such as a fining agent, a coloring agent, a defoaming agent, and a fluorine compound may be added by an appropriate amount to the glass composition as needed. In addition to the above-mentioned components, other components may be added as long as the effect of the optical glass according to the present embodiment can be exerted.
  • A method of manufacturing the optical glass according to the present embodiment is not particularly limited, and a publicly known method may be adopted. Further, suitable conditions can be selected for the manufacturing conditions as appropriate. For example, there may be adopted a manufacturing method in which raw materials such as oxides, carbonates, nitrates, and sulfates are blended to obtain a target composition, melted at a temperature of preferably from 1,100 to 1,400 degrees Celsius, uniformed by stirring, subjected to defoaming, then poured in a mold, and molded. A lower limit of the melting temperature described above is more preferably 1200 degrees Celsius. An upper limit of the melting temperature is more preferably 1350 degrees Celsius, further preferably 1300 degrees Celsius. The optical glass thus obtained is processed to have a desired shape by performing reheat pressing or the like as needed, and is subjected to polishing. With this, a desired optical element is obtained.
  • A high-purity material with a small content rate of impurities is preferably used as the raw material. The high-purity material indicates a material including 99.85 mass% or more of a concerned component. By using the high-purity material, an amount of impurities is reduced, and hence an inner transmittance of the optical glass is likely to be increased.
  • Next, description is made on physical properties of the optical glass according to the present embodiment.
  • From a viewpoint of reduction in thickness of the lens, the optical glass according to the present embodiment preferably has a high refractive index (a refractive index (nd) is large). However, in general, as the refractive index (nd) is higher, the transmittance is liable to be reduced. In view of such a circumstance, the refractive index (nd) of the optical glass according to the present embodiment with respect to a d-line preferably falls within a range from 1.60 to 1.85. A lower limit of the refractive index (nd) is more preferably 1.65. An upper limit of the refractive index (nd) is more preferably 1.80.
  • An abbe number (vd) of the optical glass according to the present embodiment preferably falls within a range from 20 to 35. A lower limit of the abbe number (νd) is more preferably 22. An upper limit of the abbe number (vd) is more preferably 30.
  • From a viewpoint of aberration correction of the lens, the optical glass according to the present embodiment preferably has a large partial dispersion ratio (Pg, F). In view of such circumstance, the partial dispersion ratio (Pg, F) of the optical glass according to the present embodiment is preferably 0.61 or more. A lower limit of the partial dispersion ratio (Pg, F) is more preferably 0.62, further preferably 0.64. An upper limit of the partial dispersion ratio (Pg, F) is not particularly limited, but may be, for example, 0.66.
  • From a viewpoint of aberration correction of the lens, the optical glass according to the present embodiment preferably has great abnormal dispersibility (ΔPg, F). In view of such circumstance, the value (ΔPg, F) indicating the abnormal dispersibility of the optical glass according to the present embodiment is preferably 0.015 or more. A lower limit of the value (ΔPg, F) indicating the abnormal dispersibility is more preferably 0.020, further preferably 0.030. An upper limit of the value (ΔPg, F) indicating the abnormal dispersibility is not particularly limited, but may be, for example, 0.055.
  • From the above-mentioned viewpoint, the optical glass according to the present embodiment can be suitably used as, for example, an optical element included in optical equipment. Such an optical element includes a mirror, a lens, a prism, a filter, and the like. Examples of an optical system in which the optical element described above is used include, for example, an objective lens, a condensing lens, an image forming lens, and an interchangeable camera lens. The optical system can be suitably used for an imaging device, such as a camera with an interchangeable lens and a camera with a non-interchangeable lens, and various optical devices such as a microscope device such as a fluorescence microscope and a multi-photon microscope. The optical device is not limited to the imaging device and the microscope described above, and also includes a telescope, a binocular, a laser range finder, a projector, and the like, which are not limited thereto. An example thereof will be described below.
  • <Imaging Device>
  • FIG. 1 is a perspective view illustrating one example of an optical device according to the present embodiment as an imaging device. An imaging device 1 is a so-called digital single-lens reflex camera (a lens-interchangeable camera), and a photographing lens 103 (an optical system) includes, as a base material, an optical element including the optical glass according to the present embodiment. A lens barrel 102 is mounted to a lens mount (not illustrated) of a camera body 101 in a removable manner. An image is formed with light, which passes through the lens 103 of the lens barrel 102, on a sensor chip (solid-state imaging elements) 104 of a multi-chip module 106 arranged on a back surface side of the camera body 101. The sensor chip 104 is a so-called bare chip such as a CMOS image sensor, and the multi-chip module 106 is, for example, a Chip On Glass (COG) type module including the sensor chip 104 being a bare chip mounted on a glass substrate 105.
  • FIGS. 2 and 3 are schematic diagrams illustrating another example of the optical device according to the present embodiment as an imaging device. FIG. 2 illustrates a front view of an imaging device CAM, and FIG. 3 illustrates a back view of the imaging device CAM. The imaging device CAM is a so-called digital still camera (a fixed lens camera), and a photographing lens WL (an optical system) includes an optical element including the optical glass according to the present embodiment, as a base material.
  • When a power button (not illustrated) of the imaging device CAM is pressed, a shutter (not illustrated) of the photographing lens WL is opened, light from an object to be imaged (a body) is converged by the photographing lens WL and forms an image on imaging elements arranged on an image surface. An object image formed on the imaging elements is displayed on a liquid crystal monitor M arranged on the back of the imaging device CAM. A photographer decides composition of the object image while viewing the liquid crystal monitor M, then presses down a release button B1 to capture the object image with the imaging elements. The object image is recorded and stored in a memory (not illustrated).
  • An auxiliary light emitting unit EF that emits auxiliary light in a case that the object is dark and a function button B2 to be used for setting various conditions of the imaging device CAM and the like are arranged on the imaging device CAM.
  • A higher resolution, low chromatic aberration, and a smaller size are demanded for the optical system to be used in such digital camera or the like. In order to achieve such demands, it is effective to use glass with dispersion characteristics different from each other as the optical system. Particularly, glass that achieves both low dispersion and a higher partial dispersion ratio (Pg, F) is highly demanded. From such a viewpoint, the optical glass according to the present embodiment is suitable as a member of such optical equipment. Note that, in addition to the imaging device described above, examples of the optical equipment to which the present embodiment is applicable include a projector and the like. In addition to the lens, examples of the optical element include a prism and the like.
  • <Microscope>
  • FIG. 4 is a block diagram illustrating an example of a configuration of a multi-photon microscope 2 according to the present embodiment. The multi-photon microscope 2 includes an objective lens 206, a condensing lens 208, and an image forming lens 210. At least one of the objective lens 206, the condensing lens 208, and the image forming lens 210 includes an optical element including, as a base material, the optical glass according to the present embodiment. Hereinafter, description is mainly made on the optical system of the multi-photon microscope 2.
  • A pulse laser device 201 emits ultrashort pulse light having, for example, a near infrared wavelength (approximately 1,000 nm) and a pulse width of a femtosecond unit (for example, 100 femtoseconds). In general, ultrashort pulse light immediately after being emitted from the pulse laser device 201 is linearly polarized light that is polarized in a predetermined direction.
  • A pulse division device 202 divides the ultrashort pulse light, increases a repetition frequency of the ultrashort pulse light, and emits the ultrashort pulse light.
  • A beam adjustment unit 203 has a function of adjusting a beam diameter of the ultrashort pulse light, which enters from the pulse division device 202, to a pupil diameter of the objective lens 206, a function of adjusting convergence and divergence angles of the ultrashort pulse light in order to correct chromatic aberration (a focus difference) on an axis of a wavelength of light emitted from a sample S and the wavelength of the ultrashort pulse light, a pre-chirp function (group velocity dispersion compensation function) providing inverse group velocity dispersion to the ultrashort pulse light in order to correct the pulse width of the ultrashort pulse light, which is increased due to group velocity dispersion at the time of passing through the optical system, and the like.
  • The ultrashort pulse light emitted from the pulse laser device 201 have a repetition frequency increased by the pulse division device 202, and is subjected to the above-mentioned adjustments by the beam adjustment unit 203. The ultrashort pulse light emitted from the beam adjustment unit 203 is reflected on a dichroic mirror 204 in a direction toward a dichroic mirror, passes through the dichroic mirror 205, is converged by the objective lens 206, and is radiated to the sample S. At this time, an observation surface of the sample S may be scanned with the ultrashort pulse light through use of scanning means (not illustrated).
  • For example, when the sample S is subjected to fluorescence imaging, a fluorescent pigment by which the sample S is dyed is subjected to multi-photon excitation in an irradiated region with the ultrashort pulse light and the vicinity thereof on the sample S, and fluorescence having a wavelength shorter than a near infrared wavelength of the ultrashort pulse light (hereinafter, also referred to "observation light") is emitted.
  • The observation light emitted from the sample S in a direction toward the objective lens 206 is collimated by the objective lens 206, and is reflected on the dichroic mirror 205 or passes through the dichroic mirror 205 depending on the wavelength.
  • The observation light reflected on the dichroic mirror 205 enters a fluorescence detection unit 207. For example, the fluorescence detection unit 207 is formed of a barrier filter, a photo multiplier tube (PMT), or the like, receives the observation light reflected on the dichroic mirror 205, and outputs an electronic signal depending on an amount of the light. The fluorescence detection unit 207 detects the observation light over the observation surface of the sample S, in conformity with the ultrashort pulse light scanning on the observation surface of the sample S.
  • Note that, all the observation light emitted from the sample S in a direction toward the objective lens 206 may be detected by the fluorescence detection unit 211 by excluding the dichroic mirror 205 from the optical path. In that case, the observation light is de-scanned by a scanning means (not illustrated), passes through the dichroic mirror 204, is converged by the condensing lens 208, passes through a pinhole 209 provided at a position substantially conjugate to a focal position of the objective lens 206, passes through the image forming lens 210, and enters a fluorescence detection unit 211.
  • For example, the fluorescence detection unit 211 is formed of a barrier filter, a PMT, or the like, receives the observation light forming an image on a light formed by the image forming lens 210 reception surface of the fluorescence detection unit 211, and outputs an electronic signal depending on an amount of the light. The fluorescence detection unit 211 detects the observation light over the observation surface of the sample S, in conformity with the ultrashort pulse light scanning on the observation surface of the sample S.
  • The observation light emitted from the sample S in a direction opposite to the objective lens 206 is reflected on a dichroic mirror 212, and enters a fluorescence detection unit 213. The fluorescence detection unit 113 is formed of, for example, a barrier filter, a PMT, or the like, receives the observation light reflected on the dichroic mirror 212, and outputs an electronic signal depending on an amount of the light. The fluorescence detection unit 213 detects the observation light over the observation surface of the sample S, in conformity with the ultrashort pulse light scanning on the observation surface of the sample S.
  • The electronic signals output from the fluorescence detection units 207, 211, and 213 are input to, for example, a computer (not illustrated). The computer is capable of generating an observation image, displaying the generated observation image, storing data on the observation image, based on the input electronic signals.
  • <Cemented Lens>
  • FIG. 5 is a schematic diagram illustrating one example of a cemented lens according to the present embodiment. A cemented lens 3 is a compound lens including a first lens element 301 and a second lens element 302. The optical glass according to the present embodiment is used as at least one of the first lens element and the second lens element. The first lens element and the second lens element are joined through intermediation with a joining member 303. As the joining member 303, a publicly known adhesive agent or the like may be used. Note that, the "lens element" refers to each lens constituting a single lens or a cemented lens.
  • The cemented lens according to the present embodiment is effective in view of correction of chromatic aberration, and can be used suitably for the optical element, the optical system, and the optical device that are described above and the like. Furthermore, the optical system including the cemented lens can be used suitably for, especially, an interchangeable camera lens and an optical device. Note that, in the aspect described above, description is made on the cemented lens using the two lens elements. The present invention is however not limited thereto, and a cemented lens using three or more lens elements may be used. When the cemented lens uses three or more lens elements, it is only required that at least one of the three or more lens elements be formed by using the optical glass according to the present embodiment.
  • Examples
  • Next, description is made on Examples in the present invention and Comparative Examples. Note that, the present invention is not limited thereto.
  • <Production of Optical Glasses>
  • The optical glasses in each example and each comparative example were produced by the following procedures. First, glass raw materials selected from oxides, hydroxides, phosphate compounds (phosphates, orthophosphoric acids, and the like), carbonates, nitrates, and the like were weighed so as to obtain the compositions (mass%) illustrated in each table. Next, the weighed raw materials were mixed and put in a platinum crucible, melted at a temperature of from 1,100 to 1,350 degrees Celsius, and uniformed by stirring. After defoaming, the resultant was lowered to an appropriate temperature, poured in a mold, annealed, and molded. In this manner, each sample was obtained.
  • <Evaluation of Physical Properties>
  • FIG. 6 is a graph in which Pg,F and νd of Examples and Comparative Examples are plotted.
  • Refractive Index (nd) and Abbe Number (νd)
  • The refractive index (nd) and the abbe number (vd) in each of the samples were measured and calculated through use of a refractive index measuring instrument (KPR-2000 manufactured by Shimadzu Device Corporation). nd indicates a refractive index of the glass with respect to light of 587.562 nm. νd was obtained based on Expression (1) given below. nc and nF indicates refractive indexes of the glass with respect to light having a wavelength of 656.273 nm and light having a wavelength of 486.133 nm, respectively. ν d = n d 1 / n F n C
    Figure imgb0001
  • Partial Dispersion Ratio (Pg,F)
  • The partial dispersion ratio (Pg,F) in each of the samples indicates a ratio of partial dispersion (ng - nF) to main dispersion (nF - nc), and was obtained based on Expression (2) given below. ng indicates a refractive index of the glass with respect to light having a wavelength of 435.835 nm. A value of the partial dispersion ratio (Pg,F) was truncated to the third decimal place. P g , F = n g n F / n F n C
    Figure imgb0002
  • Abnormal Dispersibility (ΔPg,F)
  • The abnormal dispersibility (ΔPg,F) of each sample indicates a deviation from a partial dispersion ratio standard line with reference to two types of glass of F2 and K7 as glass having normal dispersion. In other words, on coordinates with a partial dispersion ratio (Pg,F) as a vertical axis and an abbe number νd as a horizontal axis, a difference in ordinate between a straight line connecting two types of glass and a value of glass to be compared is a deviation of the partial dispersion ratio, i.e., abnormal dispersibility (ΔPg,F). In the coordinate system described above, when a value of the partial dispersion ratio is located above the straight line connecting the types of glass as a reference, glass indicates positive abnormal dispersibility (+ΔPg,F), and when the value is located below the straight line, glass indicates negative abnormal dispersibility (-ΔPg,F) . Note that, the abbe number νd and the partial dispersion ratio (Pg,F) of F2 and K7 are as follows.
    • F2: abbe number νd = 36.33, partial dispersion ratio (Pg,F) = 0.5834
    • K7: abbe number νd = 60.47, partial dispersion ratio (Pg,F) = 0.5429
    A value of abnormal dispersibility (ΔPg,F) is truncated to the third decimal place. Δ P g , F = P g , F 0.0016777 × ν d + 0.6443513
    Figure imgb0003
  • Tables 1 to 36 illustrate a composition of components by mass% in terms of an oxide and evaluation results of physical properties for optical glass of Examples and Comparative Examples. "ΣA2O" in Expressions indicates a total content rate of Li2O, Na2O, and K2O (A = Li, Na, K). "ΣEO" in Expressions indicates a total content rate of MgO, CaO, SrO, BaO, and ZnO (E = Mg, Ca, Sr, Ba, Zn). In the first to third comparative examples, the optical glass could not be obtained, and thus physical properties were "unmeasurable". [Table 1]
    MASS % EXAMPLE 1 EXAMPLE 2 EXAMPLE 3 EXAMPLE 4
    P2O5 43.11 44.31 45.40 42.92
    SiO2
    B2O3
    Li2O
    Na2O 17.82 17.06 18.13 17.14
    K2O 7.21 7.42 8. 56 8.09
    MgO
    CaO
    SrO
    BaO 8.35 7.03 5.60 5.29
    ZnO 2.24 2.31 1.54 1.45
    Al2O3 1.52 1.56
    TiO2 19.64 20.19 20.68 20.09
    ZrO2
    Nb2O5 4.94
    Sb2O3 0.11 0.12 0.09 0.09
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66633 1.67115 1.66813 1.68412
    v d 27.03 26.37 25.72 25.58
    Pg,F 0.634 0.635 0.639 0.635
    Figure imgb0004
    Pg,F
    0.035 0.035 0.038 0.034
    ∑A2O 25.03 24.48 26.69 25.23
    ∑EO 10.59 9.34 7.13 6.74
    TiO2/P2O5 0.46 0.46 0.46 0.47
    Al2O3/TiO2 0.08 0.08
    B2O3/P2O3
    TiO2/(P2O5+B2O3+Al2O3) 0.44 0.44 0.46 0.47
    TiO2/(TiO2+Nb2O6+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00 0.80
    (BaO+TiO2)/P2O5 0.65 0.61 0.58 0.59
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.63 0.59 0.58 0.71
    ∑ A2O/ TiO2 1.27 1.21 1.29 1.26
    ∑ EO/ ∑A2O 0.42 0.38 0.27 0.27
    SiO2+B2O3
    [Table 2]
    MASS % EXAMPLE 5 EXAMPLE 6 EXAMPLE 7 EXAMPLE 8
    P2O5 45.09 43.78 48.14 44.83
    SiO2
    B2O3 2.78
    Li2O 3.77
    Na2O 19.26 13.77 12.08 23.47
    K2O 6.59 7.33 8.05
    MgO
    CaO
    SrO
    BaO 8.43 8.48 6.02 5.60
    ZnO 2.28 1.58 1.47
    Al2O3 1.54
    TiO2 20.54 19.94 20.23 24.50
    ZrO2
    Nb2O5
    Sb2O3 0.09 0.12 0.13 0.12
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66718 1.67654 1.68424 1.68975
    vd 26.14 27.26 25.52 25.11
    Pg,F 0.637 0.630 0.638 0.636
    Figure imgb0005
    Pg,F
    0.036 0.032 0.036 0.033
    ∑A2O 25.85 21.09 23.90 23.47
    ∑EO 8.43 10.75 7.60 7.08
    TiO2/P2O5 0.46 0.46 0.42 0.55
    Al2O3/TiO2 0.08
    B2O3/P2O6 0.06
    TiO2/(P2O5+B2O3+Al2O3) 0.46 0.41 0.42 0.55
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00 1.00
    (BaO+TiO2)/P2O5 0.64 0.65 0.55 0.67
    (BaO+TiO2+Nb2O5 +Ta205+WO3+Bi2O3)/ (P2O5+B2O3+Si02+Al2O3) 0.64 0.59 0.55 0.67
    ∑ A2O/TiO2 1.26 1.06 1.18 0.96
    ∑ EO/∑ A2O 0.33 0.51 0.32 0.30
    SiO2+B2O3 2. 78
    [Table 3]
    MASS % EXAMPLE 9 EXAMPLE 10 EXAMPLE 11 EXAMPLE 12
    P2O5 39.64 37.13 42. 22 42. 63
    SiO2
    B2O3 3.68 3.45
    Li2O 1.77 1.20
    Na2O 18.83 13.34 10.70 13.92
    K2O 8.88 8.32 7.06 7.13
    MgO
    CaO
    SrO
    BaO 5.81 16.07 7.62 5.13
    ZnO 1.59 1.49
    Al2O3
    TiO2 21.47 20. 11 25. 75 29. 86
    ZrO2
    Nb2O5 4. 76
    Sb2O3 0.09 0.09 0.11 0.11
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66080 1.68280 1.75149 1.74476
    vd 28.20 28.16 22.52 22.16
    Pg,F 0.625 0.627 0.644 0.649
    Figure imgb0006
    Pg,F
    0.028 0.030 0.038 0.041
    ∑A2O 27.71 21.66 19.53 22.26
    ∑EO 7.40 17.56 7.62 5.13
    TiO2/P2O5 0.54 0.54 0.61 0.70
    Al2O3/TiO2
    B2O3/P2O5 0.09 0.09
    TiO2/(P2O6+B2O3+Al2O3) 0.50 0.50 0.61 0.70
    TiO2/(TiO2+Nb2O6+WO3+ Bi2O3+Ta2O5) 1.00 1.00 0.84 1.00
    (BaO+TiO2) /P205 0.69 0.97 0. 79 0.82
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 0.63 0.89 0.90 0.82
    ∑ A2O/TiO2 1.29 1.08 0.76 0.75
    ∑ EO/ ∑ A2O 0.27 0.81 0.39 0.23
    SiO2+B2O3 3.68 3.45
    [Table 4]
    MASS % EXAMPLE 13 EXAMPLE 14 EXAMPLE 15 EXAMPLE 16
    P2O5 38.46 42.50 41. 27 44. 38
    SiO2
    B2O3 2.02
    Li2O 1.78 1.02 1.86
    Na2O 11.59 11.71 14.03 12.35
    K2O 13.08 7.11 6.06 7.43
    MgO
    CaO
    SrO
    BaO 5.27 5.37 5.04 5.29
    ZnO 6.16
    Al2O3
    TiO2 18.78 26.52 32.48 28.58
    ZrO2
    Nb2O5
    Sb2O3 0.11 0.11 0.10 0.12
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3 4.52 4.90
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.67852 1.75015 1.75766 1.81066
    v d 27.26 22,30 21.99 23.02
    Pg,F 0.630 0.645 0.647 0.634
    Figure imgb0007
    Pg,F
    0.031 0.039 0.039 0.028
    ∑A2O 24.67 20.59 21.11 21.64
    ∑EO 11.43 5. 37 5. 04 5. 29
    TiO2/P2O5 0.49 0.62 0.79 0.64
    Al2O3/TiO2
    B2O3/P2O5 0.05
    TiO2/(P2O5+B2O3+Al2O3) 0.46 0.62 0.79 0.64
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.81 0.84 1.00 1.00
    (BaO+TiO2)/P2O5 0.63 0.75 0.91 0.76
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 0.71 0.87 0.91 0.76
    ∑ A2O/TiO2 1.31 0.78 0.65 0.76
    ∑ EO/∑ A2O 0.46 0.26 0.24 0.24
    SiO2+B2O3 2.02
    [Table 5]
    MASS % EXAMPLE 17 EXAMPLE 18 EXAMPLE 19 EXAMPLE 20
    P2O5 45.00 44.32 43.47 42.87
    SiO2
    B2O3
    Li2O 2.60
    Na2O 19.27 17.97 17. 72
    K2O 19. 87 7.42 7.27 7. 17
    Mg O
    CaO
    SrO
    BaO 11.86 5.49 6.17 6.09
    ZnO 2.34 1.49 2.26 2.23
    Al2O3 1.80
    TiO2 16.41 18.57 18.22 17.97
    ZrO2
    Nb2O5 2.68
    Sb2O3 0.12 0.06 0.06 0.06
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3 0.70 4.59 4.52
    Bi2O3 1.36
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.65697 1.66138 1.66615 1.66908
    v d 28.39 26.85 26.50 26.50
    Pg,F 0.627 0.631 0.633 0.635
    Figure imgb0008
    Pg,F
    0.030 0.032 0.033 0.035
    ∑ A2O 22.48 26. 68 25. 24 24. 89
    ∑ EO 14.20 6.98 8.43 8.32
    TiO2/P2O5 0.36 0.42 0.42 0.42
    Al2O3/TiO2 0.11
    B2O3/P2O5
    TiO2/(P2O5+B2O3+Al2O3) 0.35 0.42 0.42 0.42
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 0.85 0.80 0.75
    (BaO+TiO2)/P2O5 0.63 0.54 0.56 0.56
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.60 0.62 0.67 0.70
    ∑ A2O/TiO2 1.37 1.44 1.39 1.39
    ∑ EO/ ∑A2O 0.63 0.26 0.33 0.33
    SiO2+B2O3
    [Table 6]
    MASS % EXAMPLE 21 EXAMPLE 22 EXAMPLE 23 EXAMPLE 24
    P2O5 44.34 41.09 46.69 45.90
    SiO2 1.11
    B2O3
    Li2O 0.61 0.69 0.68
    Na2O 18.32 12.42 14.11 13.87
    K2O 7.42 7.74 8.80 8.65
    MgO 4.40
    CaO 6.02
    SrO
    BaO 6.30 21.81 8.02 7.89
    ZnO 2.31
    Al2O3
    TiO2 18.58 15.11 17.17 16.88
    ZrO2
    Nb2O5 2.68
    Sb2O3 0.06 0.11 0.12 0.12
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66545 1.66162 1.65551 1.65787
    v d 26.72 28.95 28.23 28.57
    Pg,F 0.633 0.630 0.633 0.631
    Figure imgb0009
    Pg,F
    0.034 0.034 0.036 0.034
    ∑ A2O 25.74 20.76 23.59 23.19
    ∑ EO 8.60 21.81 12.43 13.91
    TiO2/P2O5 0.42 0.37 0.37 0.37
    Al203/TiO2
    B203/P2O5
    TiO2/(P2O5+B2O3+Al2O3) 0.42 0.37 0.37 0.37
    TiO2/(TiO2+Nb2O5+WO3+ Bi203+Ta2O5) 0.87 1.00 1.00 1.00
    (BaO+TiO2)/P2O5 0.56 0.90 0.54 0.54
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.62 0.87 0.54 0.54
    ∑ A2O/TiO2 1.39 1.37 1.37 1.37
    ∑ EO/ΣA2O 0.33 1.05 0.53 0.60
    SiO2+B2O3 1.11
    [Table 7]
    MASS % EXAMPLE 25 EXAMPLE 26 EXAMPLE 27 EXAMPLE 28
    P2O5 43.67 40.86 40.93 40.86
    SiO2
    B2O3
    Li2O 0.64 0.60 0.60 0.60
    Na2O 13.19 12.35 12.37 12.35
    K2O 8.23 7.70 7.71 7.70
    MgO
    CaO
    SrO 10.59
    BaO 7.51 21.69 21.72 21.69
    ZnO
    Al2O3
    TiO2 16.06 15.03 15.05 15.03
    ZrO2
    Nb2O5
    Sb2O3 0.12 0.11 0.11 0.11
    Ta2O5
    Y2O3 1.66
    La2O3 1.50
    Gd2O3 1.67
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.65953 1.66630 1.66633 1.66635
    vd 28.67 29.13 29.05 28.96
    Pg,F 0.631 0.630 0.630 0.631
    Figure imgb0010
    Pg,F
    0.035 0.035 0.034 0.035
    ∑A2O 22.06 20.65 20.68 20.65
    ∑EO 18.09 21.69 21.72 21.69
    TiO2/P2O5 0.37 0.37 0.37 0.37
    Al2O3/TiO2
    B203/P205
    TiO2/ (P2O3+B2O3+Al2O3) 0.37 0.37 0.37 0.37
    TiO2/ (TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00 1.00
    (Ba0+Ti02)/P205 0.54 0.90 0.90 0.90
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.54 0.90 0.90 0.90
    ∑ A2O/TiO2 1.37 1.37 1.37 1.37
    ∑ EO/ΣA2O 0.82 1.05 1.05 1.05
    SiO2+B2O3
    [Table 8]
    MASS % EXAMPLE 29 EXAMPLE 30 EXAMPLE 31 EXAMPLE 32
    P2O5 40. 96 41. 13 41.60 44. 31
    SiO2
    B2O3
    Li2O 0.60 0.61 0.61
    Na2O 12.38 12.43 12.57 17.06
    K2O 7.72 7.75 7.84 7.42
    MgO
    CaO
    SrO
    BaO 21.74 21.83 22.08 7.03
    ZnO 2.31
    Al2O3 1.56
    TiO2 15.06 15.13 15.30 20.19
    ZrO2 1.03
    Nb2O5
    Sb2O3 0.11 0.11 0.12
    Ta2O5 1.42
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66723 1.66720 1.66413 1.67115
    ν d 28.70 28.96 28.76 26.37
    Pg,F 0.630 0.632 0.633 0.635
    Figure imgb0011
    Pg,F
    0.034 0.036 0.036 0.035
    ∑ A2O 20.70 20.78 21.02 24.48
    ∑ EO 21.74 21.83 22.08 9.34
    TiO2/P2O5 0.37 0.37 0.37 0.46
    Al203/Ti02 0.08
    B2O3/P2O5
    TiO2/(P2O5+B2O3+Al2O3) 0.37 0.37 0.37 0.44
    TiO2/(TiO2+Nb2O6+WO3+ Bi2O3+Ta2O5) 0.91 1.00 1.00 1.00
    (BaO+TiO2)/P2O5 0.90 0.90 0.90 0.61
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.93 0.90 0.90 0.59
    ∑ A2O/TiO2 1.37 1.37 1.37 1.21
    ∑ EO/ ∑A2O 1.05 1.05 1.05 0.38
    SiO2+B2O3
    [Table 9]
    MASS % EXAMPLE 33 EXAMPLE 34 EXAMPLE 35 EXAMPLE 36
    P2O5 45.40 42.92 45.09 43.78
    SiO2
    B2O3 2.78
    Li2O
    Na2O 18.13 17.14 19.26 13.77
    K2O 8.56 8.09 6.59 7.33
    MgO
    CaO
    SrO
    BaO 5.60 5.29 8.43 8.48
    ZnO 1.54 1.45 2.28
    Al2O3 1.54
    TiO2 20.68 20.09 20.54 19.94
    ZrO2
    Nb2O5 4.94
    Sb2O3 0.09 0.09 0.09 0.12
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66813 1.68412 1.66718 1.67654
    Vd 25.72 25.58 26.14 27.26
    Pg,F 0.639 0.635 0.637 0.630
    Figure imgb0012
    Pg,F
    0.038 0.034 0.036 0.032
    ∑ A2O 26.69 25.23 25.85 21.09
    ∑ EO 7.13 6.74 8.43 10.75
    TiO2/P2O5 0.46 0.47 0.46 0.46
    Al2O3/TiO2 0.08
    B2O3/P2O5 0.06
    TiO2/(P2O3+B2O3+Al2O3) 0.46 0.47 0.46 0.41
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 0.80 1.00 1.00
    (BaO+TiO2)/P2O5 0.58 0.59 0.64 0.65
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.58 0.71 0.64 0.59
    ∑ A2O/TiO2 1.29 1.26 1.26 1.06
    ∑ EO/ ∑ A2O 0.27 0.27 0.33 0.51
    SiO2+B2O3 2.78
    [Table 10]
    MASS % EXAMPLE 37 EXAMPLE 38 EXAMPLE 39 EXAMPLE 40
    P2O5 48.14 44.83 39.64 37.13
    SiO2
    B2O3 3.68 3.45
    Li2O 3.77
    Na2O 12.08 23.47 18.83 13.34
    K2O 8.05 8.88 8.32
    MgO
    CaO
    SrO
    BaO 6.02 5.60 5.81 16.07
    ZnO 1.58 1.47 1.59 1.49
    Al2O3
    TiO2 20.23 24.50 21.47 20.11
    ZrO2
    Nb2O5
    Sb2O3 0.13 0.12 0.09 0.09
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.68424 1.68975 1.66080 1.68280
    ν d 25.52 25.11 28.20 28.16
    Pg,F 0.638 0.636 0.625 0.627
    Figure imgb0013
    Pg, F
    0.036 0.033 0.028 0.030
    ∑A2O 23.90 23.47 27.71 21.66
    ∑EO 7.60 7.08 7.40 17.56
    TiO2/P2O5 0.42 0. 55 0.54 0.54
    Al2O3/TiO2
    B2O3/P2O5 0.09 0.09
    TiO2/(P2O5+B2O3+Al2O3) 0.42 0.55 0.50 0.50
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00 1.00
    (BaO+TiO2)/P2O5 0.55 0.67 0.69 0.97
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.55 0.67 0.63 0.89
    ∑ A2O/TiO2 1.18 0.96 1.29 1.08
    ∑ EO/∑ A2O 0.32 0.30 0.27 0.81
    SiO2+B2O3 3.68 3.45
    [Table 11]
    MASS % EXAMPLE 41 EXAMPLE 42 EXAMPLE 43 EXAMPLE 44
    P2O5 35.25 34. 54 32.62 35.11
    SiO2
    B2O3
    Li2O 0.99 0.97 0.92
    Na2O 11.51 11.28 10.65 11.92
    K2O 5.90 5.78 5.46 5.18
    MgO
    CaO
    SrO
    BaO
    ZnO
    Al2O3 1.81 1.77 1.67 1.59
    TiO2 20.57 20.16 17.09 16.23
    ZrO2
    Nb2O5
    Sb2O3 0.09 0.09 0.09 0.08
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3 7.80 5.66 9.09 8.63
    Bi2O3 16.08 19.75 22.41 21.27
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.76276 1.76663 1.77271 1.75803
    ν d 23.06 23.25 23.37 23.44
    Pg, F 0.639 0.637 0.636 0.638
    Figure imgb0014
    Pg, F
    0.034 0.032 0.030 0.033
    ∑ A2O 18.40 18.03 17.03 17.10
    ∑ EO
    TiO2/P2O5 0.58 0.58 0.52 0.46
    Al2O3/TiO2 0.09 0.09 0.10 0.10
    B2O3/P2O5
    TiO2/(P2O5+B2O3+Al2O3) 0.56 0.56 0.50 0.44
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.46 0.44 0.35 0.35
    (BaO+TiO2) /P2O5 0.58 0.58 0.52 0.46
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 1.20 1.25 1.42 1.26
    ∑ A2O/TiO2 0.89 0.89 1.00 1.05
    ∑ EO/ ΣA2O
    SiO2+B2O3
    [Table 12]
    MASS % EXAMPLE 45 EXAMPLE 46 EXAMPLE 47 EXAMPLE 48
    P2O5 30.71 36.47 37.93 30.35
    SiO2
    B2O3
    Li2O
    Na2O 10.03 12.38 12.88 9.91
    K2O 5.14 5.38 5.60 5.08
    MgO
    CaO
    SrO
    BaO
    ZnO
    Al2O3 1.57 1.65 1.71 1.55
    TiO2 16.09 16.85 17.53 15.31
    ZrO2
    Nb2O5
    Sb2O3 0.08 0.09 0.09 0.08
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3 15.28 12.80 17.31 16.85
    Bi2O3 21.10 14.39 6.95 20.86
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.78911 1.74422 1.72734 1.78605
    νd 22.50 23.56 23.89 22.69
    Pg,F 0.639 0.638 0.637 0.637
    Figure imgb0015
    Pg,F
    0.033 0.033 0.033 0.031
    ∑A2O 15.17 17.76 18.48 14.99
    ∑EO
    TiO2/P2O5 0.52 0.46 0.46 0.50
    Al2O3/TiO2 0.10 0.10 0.10 0.10
    B2O3/P2O5
    TiO2/ (P2O5+B2O3+Al2O3) 0.50 0.44 0.44 0.48
    TiO2/ (TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.31 0.38 0.42 0.29
    (BaO+TiO2) /P2O5 0.52 0.46 0.46 0.50
    (BaO+TiO2+Nb2O5 +Ta2O3+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 1.63 1.16 1.05 1.66
    ∑ A2O/TiO2 0.94 1.05 1.05 0.98
    ∑ EO/ ∑ A2O
    SiO2+B2O3
    [Table 13]
    MASS % EXAMPLE 49 EXAMPLE 50 EXAMPLE 51 EXAMPLE 52
    P2O5 33.24 29.67 38.86 36.59
    SiO2
    B2O3
    Li2O 0.94 1.62 2.90
    Na2O 14.51 7.41 12.69 15.98
    K2O 4.97 6.50
    MgO
    CaO
    SrO
    BaO 5.64
    ZnO
    Al2O3 1.70 1.52
    TiO2 17.42 15.55 21.88 19.18
    ZrO2
    Nb2O5
    Sb2O3 0.09 0.08 0.10 0.10
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3 9.27 14.77
    Bi2O3 22.84 20.39 18.34 25.27
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.77604 1.80301 1.75238 1.75526
    v d 23.54 22.62 23.10 24.47
    Pg,F 0.634 0.638 0.639 0.629
    Figure imgb0016
    Pg,F
    0.029 0.031 0.033 0.026
    ∑A2O 15.45 12.38 20.82 18.87
    ∑EO 5.64
    TiO2/P2O5 0.52 0.52 0.56 0.52
    Al2O3/TiO2 0.10 0.10
    B2O3/P2O5
    TiO2/ (P2O5+B2O3+Al2O3) 0.50 0.50 0.56 0.52
    TiO2/ (TiO2+Nb2O6+WO3+ Bi2O3+Ta2O5) 0.35 0.31 0.54 0.43
    (BaO+TiO2) /P2O5 0.52 0.71 0.56 0.52
    (BaO+TiO2+Nb2O5 +Ta2O3+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 1.42 1.81 1.03 1.21
    ∑ A2O/TiO2 0.89 0.80 0.95 0.98
    ∑ EO/∑ A2O 0.46
    SiO2+B2O3
    [Table 14]
    MASS % EXAMPLE 53 EXAMPLE 54 EXAMPLE 55 EXAMPLE 56
    P2O5 28.71 42.65 36.90 42.21
    SiO2 1.09
    B2O3
    Li2O 2.47 1.54
    Na2O 4.97 9.35 14.33
    K2O 4.80 18.83 6.17 6.23
    MgO
    CaO
    SrO
    BaO 10.91 11.23 6.66
    ZnO 2.22 2.14
    Al2O3 1.47 1.50
    TiO2 15.05 15.55 20.77 22.19
    ZrO2
    Nb2O5
    Sb2O3 0.08 0.11 0.10 0.10
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3 14.29
    Bi2O3 19.73 5.43 17.41 12.80
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.81066 1.67374 1.76767 1.73607
    νd 23.02 27.62 22.94 22.88
    Pg,F 0.634 0.627 0.640 0.639
    Figure imgb0006
    Pg.F
    0.028 0.029 0.035 0.033
    ∑ A2O 9.77 21.30 17.07 20.56
    ∑ EO 10.91 13.46 6.66 2.14
    TiO2/P2O5 0.52 0.36 0.56 0.53
    Al2O3/TiO2 0.10 0.10
    B2O3/P2O5
    TiO2/(P2O5+B2O3+Al2O3) 0.50 0.35 0.56 0.53
    TiO2/ (TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.31 0.74 0.54 0.63
    (BaO+TiO2)/P2O5 0.90 0.63 0.74 0.53
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 1.99 0.73 1.18 0.83
    ∑ A2O/TiO2 0.65 1.37 0.82 0.93
    ∑ EO/∑ A2O 1.12 0.63 0.39 0.10
    SiO2+B2O3 1.09
    [Table 15]
    MASS % EXAMPLE 57 EXAMPLE 58 EXAMPLE 59 EXAMPLE 60
    P2O5 29.37 29.41 29.31 29.01
    SiO2
    B2O3 1.01
    Li2O
    Na2O 7.34 7.35 7.32 7.25
    K2O 4.92 4.92 4.90 4.85
    MgO 0.88
    CaO 1.22
    SrO 2.23
    BaO 5.58 5.59 5.57 5.51
    ZnO
    Al2O3 1.50 1.51 1.50 1.49
    TiO2 15.40 15.42 15. 36 15.21
    ZrO2
    Nb2O5
    Sb2O3 0.08 0.08 0.08 0.08
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3 14.62 14.64 14.59 14.44
    Bi2O3 20.18 20.21 20.14 19.93
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.79468 1.79736 1.79719 1.79614
    νd 23.17 23.06 23.21 23.29
    Pg,F 0.634 0.637 0.636 0.635
    Figure imgb0006
    Pg,F
    0.029 0.031 0.031 0.030
    ∑ A2O 12.25 12.27 12.23 12.10
    ∑ EO 5.58 6.47 6.79 7.75
    TiO2/P2O5 0.52 0.52 0.52 0.52
    Al2O3/TiO2 0.10 0.10 0.10 0.10
    B2O3/P2O5 0.03
    TiO2/ (P2O6+B2O3+Al2O3) 0.48 0.50 0.50 0.50
    TiO2/ (TiO2+Nb2O6+WO3+ Bi2O3+Ta2O5) 0.31 0.31 0.31 0.31
    (BaO+TiO2) /P2O5 0.71 0.71 0.71 0.71
    (BaO+TiO2+Nb2O5 +Ta2O3+WO3+Bi2O3) / (P2O5+B21O3+SiO2+Al2O3) 1.75 1.81 1.81 1.81
    ∑ A2O/TiO2 0.80 0.80 0.80 0.80
    ∑ EO/ ∑ A2O 0.46 0.53 0.56 0.64
    SiO2+B2O3 1.01
    [Table 16]
    MASS % EXAMPLE 61 EXAMPLE 62 EXAMPLE 63 EXAMPLE 64
    P2O5 29.41 29.11 28.74 29.19
    SiO2
    B2O3
    Li2O
    Na2O 7.34 7.27 7.18 7.29
    K2O 4.92 4.87 4.81 4.88
    MgO
    CaO
    SrO
    BaO 5.59 5.53 5.46 5.55
    ZnO
    Al2O3 1.51 1.49 1.47 1.50
    TiO2 15.41 15.25 15.06 15.30
    ZrO2 0.90
    Nb2O5 1.92
    Sb2O3 0.08 0.08 0.08 0.08
    Ta2O5 3.15
    Y2O3 1.63
    La2O3
    Gd2O3
    WO3 14.64 14.48 14.30 14.53
    Bi2O3 20.21 20.00 19.75 20.06
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.79949 1.80754 1.80652 1.79792
    νd 23.01 22.57 22.70 23.21
    Pg,F 0.635 0.637 0.634 0.636
    Figure imgb0006
    Pg,F
    0.029 0.031 0.027 0.030
    ∑ A2O 12.27 12.14 11.99 12.17
    ∑ EO 5.59 5.53 5.46 5.55
    TiO2/P2O5 0.52 0.52 0.52 0.52
    Al2O3/TiO2 0.10 0.10 0.10 0.10
    B2O3/P2O5
    TiO2/ (P2O5+B2O3+Al2O3) 0.50 0.50 0.50 0.50
    TiO2/ (TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.31 0. 30 0. 29 0.31
    (BaO+TiO2) /P2O5 0.71 0.71 0.71 0.71
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 1.81 1.87 1.91 1.81
    ∑ A2O/TiO2 0.80 0.80 0.80 0.80
    ∑ EO/ ∑ A2O 0.46 0.46 0.46 0.46
    SiO2+B2O3
    [Table 17]
    MASS % EXAMPLE 65 EXAMPLE 66 EXAMPLE 67 EXAMPLE 68
    P2O5 28.90 29.36 28.73 28.66
    SiO2
    B2O3
    Li2O
    Na2O 7.22 7.33 7.17 7.16
    K2O 4.84 4.91 4.81 4.80
    Mg O
    CaO
    SrO
    BaO 5.49 5.58 5.46 5.45
    ZnO
    Al2O3 1.48 1. 50 1. 47 1. 47
    TiO2 15.15 15.39 15.06 15.02
    ZrO2
    Nb2O5 4.92 15.01
    Sb2O3 0.08 0.08
    Ta2O5
    Y2O3
    La2O3 1.07
    Gd2O3 2.60
    WO3 14.38 14.61 12.65 2.74
    Bi2O3 19.86 20.17 19.74 19.70
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.80073 1.80153 1.81591 1.83290
    ν d 23.13 22.91 22.36 21.96
    Pg,F 0.634 0.632 0.639 0.638
    Figure imgb0006
    Pg,F
    0.028 0.026 0.032 0.031
    ∑ A2O 12.06 12.24 11.98 11.96
    ∑ EO 5.49 5.58 5.46 5.45
    TiO2/P2O5 0.52 0.52 0.52 0.52
    Al2O3/TiO2 0.10 0.10 0.10 0.10
    B2O3/P2O5
    TiO2/ (P2O5+B2O3+Al2O3) 0.50 0.50 0.50 0.50
    TiO2/ (TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.31 0.31 0.29 0.29
    (BaO+TiO2)/P2O5 0.71 0.71 0.71 0.71
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 1.81 1.81 1.91 1.92
    ∑ A2O/TiO2 0.80 0.80 0.80 0.80
    ∑ EO/ ∑ A2O 0.46 0.46 0.46 0.46
    SiO2+B2O3
    [Table 18]
    MASS % EXAMPLE 69 EXAMPLE 70 EXAMPLE 71 EXAMPLE 72
    P2O5 45.89 46.96 45.20 44.85
    SiO2
    B2O3
    Li2O
    Na2O 18.96 19.41 18.68 17.27
    K2O 7.68 7.86 7.56 9.43
    MgO
    CaO
    SrO
    BaO 4.08 4.17 4.02 3.99
    ZnO 2.39 2.44 2.35 2.33
    Al2O3 1.62 1.66 1.59 1.58
    TiO2 19.39 17.51 20.59 20.43
    ZrO2
    Nb2O5
    Sb2O3 0.12
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.61155 1.63762 1.65940 1.66443
    νd 31.26 28.58 26.87 26.27
    Pg,F 0.618 0.627 0.633 0.636
    Figure imgb0007
    Pg,F
    0.027 0.031 0.033 0.036
    ∑ A2O 26.64 27.26 26.24 26.70
    ∑ EO 6.47 6.62 6.37 6.32
    TiO2/P2O5 0.42 0.37 0.46 0.46
    Al2O3/TiO2 0.08 0.09 0.08 0.08
    B2O3/P2O5
    TiO2/ (P2O5+B2O3+Al2O3) 0.41 0.36 0.44 0.44
    TiO2/ (TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00 1.00
    (BaO+TiO2)/P2O5 0.51 0.46 0.54 0.54
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 0.49 0.45 0.53 0.53
    ∑ A2O/TiO2 1.37 1.56 1.27 1.31
    ∑ EO/ ∑ A2O 0.24 0.24 0.24 0.24
    SiO2+B2O3
    [Table 19]
    MASS % EXAMPLE 73 EXAMPLE 74 EXAMPLE 75 EXAMPLE 76
    P2O5 45.11 47.45 44.73 44.20
    SiO2 0.92
    B2O3 0.71 2.10
    Li2O
    Na2O 18.01 17.88 18.49 18.27
    K2O 7.55 7.24 7.49 7.40
    Mg O
    CaO
    SrO
    BaO 4.01 3.84 3.98 3.93
    ZnO 2.35 2.25 2.33 2.30
    Al2O3 1.59 1.52 1.58 1.56
    TiO2 20.55 19.70 20.38 20.13
    ZrO2
    Nb2O5
    Sb2O3 0.12 0.11 0.12 0.12
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66496 1.66163 1.66204 1.65893
    νd 26.67 26.47 26.63 27.67
    Pg,F 0.633 0.634 0.633 0.629
    Figure imgb0007
    Pg,F
    0.033 0.034 0.034 0.031
    ∑ A2O 25.56 25.11 25.97 25.66
    ∑ EO 6.36 6.10 6.30 6.23
    TiO2/P2O5 0.46 0.42 0.46 0.46
    Al2O3/TiO2 0.08 0.08 0.08 0.08
    B2O3/P2O5 0.02 0.05
    TiO2/ (P2O5+B2O3+Al2O3) 0.43 0.40 0.44 0.42
    TiO2/ (TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00 1.00
    (BaO+TiO2)/P2O5 0.54 0. 50 0.54 0.54
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 0.52 0.48 0.52 0.50
    ∑ A2O/TiO2 1.24 1.27 1.27 1.27
    ∑ EO/ ∑ A2O 0.25 0.24 0.24 0.24
    SiO2+B2O3 0.71 0.92 2.10
    [Table 20]
    MASS % EXAMPLE 77 EXAMPLE 78 EXAMPLE 79 EXAMPLE 80
    P2O5 44.73 44.30 43.87 44.59
    SiO2
    B2O3
    Li2O 0.91
    Na2O 18.49 20.18 18.13 18.43
    K2O 7.49 7.41 10.16 7.46
    MgO 1.23
    CaO
    SrO
    BaO 3.98 3.94 3.90 3.96
    ZnO 2.33 2.31 2.28 2.32
    Al2O3 1.58 1.56 1.55 1.57
    TiO2 20.38 20.18 19.99 20.31
    ZrO2
    Nb2O5
    Sb2O3 0.12 0.12 0.12 0.12
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66592 1.65721 1.65541 1.66062
    νd 26.59 27.16 27.01 27.17
    Pg,F 0.635 0.632 0.634 0.630
    Figure imgb0007
    Pg,F
    0.035 0.033 0.035 0.031
    ∑ A2O 26.89 27.60 28.30 25.89
    ∑ EO 6.30 6.24 6.18 7.51
    TiO2/P2O5 0.46 0.46 0.46 0.46
    Al2O3/TiO2 0.08 0.08 0.08 0.08
    B2O3/P2O5
    TiO2/(P2O5+B2O3+Al2O3) 0.44 0.44 0.44 0.44
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00 1.00
    (BaO+TiO2)/P2O5 0.54 0.54 0.54 0.54
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.53 0.53 0.53 0.53
    ∑ A2O/TiO2 1.32 1.37 1.42 1.27
    ∑ EO/ ∑ A2O 0.23 0.23 0.22 0.29
    SiO2+B2O3
    [Table 21]
    MASS % EXAMPLE 81 EXAMPLE 82 EXAMPLE 83 EXAMPLE 84
    P2O5 44.38 43.11 44.04 44.06
    SiO2
    B2O3
    Li2O
    Na2O 18.34 17.82 18.20 18.21
    K2O 7.43 7.21 7.37 7.37
    MgO
    CaO 1.70
    SrO
    BaO 3.94 8.35 3.91 3.92
    ZnO 2.31 2.24 4.74 2.29
    Al2O3 1.56 1.52 1.55 1.55
    TiO2 20.22 19.64 20.06 22.48
    ZrO2
    Nb2O5
    Sb2O3 0.12 0.11 0.12 0.12
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66410 1.66633 1.66526 1.67912
    νd 27.00 27.03 26.78 25.50
    Pg,F 0.633 0.634 0.633 0.637
    Figure imgb0007
    Pg,F
    0.034 0.035 0.034 0.035
    ∑ A2O 25.77 25.03 25.57 25.58
    ∑ EO 7.95 10.59 8.65 6.21
    TiO2/P2O5 0.46 0.46 0.46 0.51
    Al2O3/TiO2 0.08 0.08 0.08 0.07
    B2O3/P2O5
    TiO2/ (P2O5+B2O3+Al2O3) 0.44 0.44 0.44 0.49
    TiO2/ (TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00 1.00
    (BaO+TiO2) /P2O5 0.54 0.65 0. 54 0.60
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.53 0.63 0.53 0.58
    ∑ A2O/TiO2 1.27 1.27 1.27 1.14
    ∑ EO/ ∑ A2O 0.31 0.42 0.34 0.24
    SiO2+B2O3
    [Table 22]
    MASS % EXAMPLE 85 EXAMPLE 86 EXAMPLE 87 EXAMPLE 88
    P2O5 44.58 42.13 39.48 43.68
    SiO2
    B2O3
    Li2O
    Na2O 18.43 17.41 16.31 18.05
    K2O 7.46 7.05 6.61 7.31
    MgO
    CaO
    SrO
    BaO 3.96 3. 75 3. 51 3.88
    ZnO 2.32 2.19 2.05 2.27
    Al2O3 1.57 1.49 1.39 1.54
    TiO2 20.31 19.19 17.98 19.90
    ZrO2 1.25
    Nb2O5
    Sb2O3 0.12 0.11 0.10 0.12
    Ta2O5
    Y2O3
    La2O3 3.24
    Gd2O3
    WO3 6.67
    Bi2O3 12.56
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66738 1.67562 1.69631 1.66770
    νd 26.56 26.17 25.90 27.01
    Pg,F 0.634 0.632 0.632 0.634
    Figure imgb0007
    Pg,F
    0.035 0.032 0.031 0.035
    ∑ A2O 25.89 24.46 22.92 25.36
    ∑ EO 6.28 5.94 5. 56 6.16
    TiO2/P2O5 0.46 0.46 0.46 0.46
    Al2O3/TiO2 0.08 0.08 0.08 0.08
    B2O3/P2O5
    TiO2/ (P2O5+B2O3+Al2O3) 0.44 0.44 0.44 0.44
    TiO2/ (TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 0.74 0.59 1.00
    (BaO+TiO2)/P2O5 0.54 0.54 0.54 0.54
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 0.53 0.68 0.83 0.53
    ∑ A2O/TiO2 1.27 1.27 1.27 1.27
    ∑ EO/ ∑ A2O 0.24 0.24 0.24 0.24
    SiO2+B2O3
    [Table 23]
    MASS % EXAMPLE 89 EXAMPLE 90 EXAMPLE 91 EXAMPLE 92
    P2O5 44.12 43.53 45.08 45.20
    SiO2
    B2O3 1.43
    Li2O
    Na2O 18.24 17.99 17.36 17.41
    K2O 7.38 7.28 7.54 7.56
    MgO
    CaO 1.15
    SrO
    BaO 3.92 3.87 4.01 4.02
    ZnO 2.30 2.27 2.35 2.35
    Al2O3 1.56 1.53 1.59 1.59
    TiO2 20.10 19.83 20.53 20.59
    ZrO2
    Nb2O5
    Sb2O3 0.12 0.12 0.12 0.12
    Ta2O5
    Y2O3 2.27
    La2O3
    Gd2O3 3.59
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66421 1.66575 1.66525 1.66963
    νd 27.13 27.13 26.62 26.35
    Pg,F 0.632 0.633 0.634 0.635
    Figure imgb0007
    Pg,F
    0.033 0.034 0.035 0.035
    ∑ A2O 25.62 25.27 24.90 24.97
    ∑ EO 6.22 6.13 6.35 7.52
    TiO2/P2O5 0.46 0.46 0.46 0.46
    Al2O3/TiO2 0.08 0.08 0.08 0.08
    B2O3/P2O5 0.03
    TiO2/ (P2O5+B2O3+Al2O3) 0.44 0.44 0.43 0.44
    TiO2/ (TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00 1.00
    (BaO+TiO2)/P2O5 0.54 0.54 0.54 0.54
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 0.53 0.53 0.51 0.53
    ∑ A2O/TiO2 1.27 1.27 1.21 1.21
    ∑ EO/ ∑ A2O 0.24 0.24 0.26 0.30
    SiO2+B2O3 1.43
    [Table 24]
    MASS % EXAMPLE 93 EXAMPLE 94 EXAMPLE 95 EXAMPLE 96
    P2O5 44.97 43.68 42.52 45.01
    SiO2
    B2O3 2.85
    Li2O
    Na2O 17.32 16.82 16.37 16.06
    K2O 7.52 7.31 7.11 7.53
    MgO
    CaO
    SrO
    BaO 4.00 3.88 3.78 4.00
    ZnO 4.01 2.27 2.21 2.34
    Al2O3 1.59 1.54 1.50 1.59
    TiO2 20.48 19.90 19.37 20.50
    ZrO2
    Nb2O5
    Sb2O3 0.12 0.12 0.11 0.12
    Ta2O5
    Y2O3 4.49
    La2O3
    Gd2O3 7.02
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.67205 1.67080 1.67218 1.66750
    νd 26.06 27.22 27.43 27.23
    Pg,F 0.635 0.631 0.631 0.631
    Figure imgb0016
    Pg,F
    0.035 0.033 0.033 0.032
    ∑ A2O 24.84 24.13 23.49 23.59
    ∑ EO 8.00 6.16 5.99 6.34
    TiO2/P2O5 0.46 0.46 0.46 0.46
    Al2O3/TiO2 0.08 0.08 0.08 0.08
    B2O3/P2O5 0.06
    TiO2/ (P2O5+B2O3+Al2O3) 0.44 0.44 0.44 0.41
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00 1.00
    (BaO+TiO2)/P2O5 0.54 0.54 0.54 0.54
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 0.53 0.53 0.53 0.50
    ∑ A2O/TiO2 1.21 1.21 1.21 1.15
    ∑ EO/ ∑ A2O 0.32 0.26 0.26 0.27
    SiO2+B2O3 2.85
    [Table 25]
    MASS % EXAMPLE 97 EXAMPLE 98 EXAMPLE 99 EXAMPLE 100
    P2O5 44.83 44.04 44.22 44.94
    SiO2
    B2O3 2.84 4.27
    Li2O
    Na2O 14.73 18.20 17.65 14.77
    K2O 7.50 7.37 7.40 7.52
    Mg O
    CaO
    SrO
    BaO 3.98 3.91 3.93 3.99
    ZnO 3.99 2.29 2.30 2.34
    Al2O3 1.58 1.56 1.58
    TiO2 20.42 24.07 20.14 20.47
    ZrO2
    Nb2O5 2.68
    Sb2O3 0.12 0.12 0.12 0.12
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.67309 1.69090 1.67300 1.66650
    νd 27.07 24.49 26.29 27.78
    Pg,F 0.631 0.640 0.634 0.628
    Figure imgb0011
    Pg,F
    0.032 0.037 0.034 0.031
    ∑ A2O 22.23 25.57 25.05 22.29
    ∑ EO 7.98 6.21 6.23 6.33
    TiO2/P2O5 0.46 0.55 0.46 0.46
    Al2O3/TiO2 0.08 0.08 0.08
    B2O3/P2O5 0.06 0.10
    TiO2/ (P2O5+B2O3+Al2O3) 0.41 0.55 0.44 0.40
    TiO2/ (TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 0.88 1.00
    (BaO+TiO2) /P2O5 0.54 0.64 0.54 0.54
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 0.50 0.64 0.58 0.48
    ∑ A2O/TiO2 1.09 1.06 1.24 1.09
    ∑ EO/ ∑ A2O 0.36 0.24 0.25 0.28
    SiO2+B2O3 2.84 4.27
    [Table 26]
    MASS % EXAMPLE 101 EXAMPLE 102 EXAMPLE 103 EXAMPLE 104
    P2O5 44.94 45.09 44.90 44.61
    SiO2
    B2O3 4.27 1.42
    Li2O
    Na2O 14.77 19.26 16.02 14.66
    K2O 7.52 6.59 7.51 7.47
    MgO
    CaO
    SrO
    BaO 3.99 8.43 3.99 3.97
    ZnO 2.34 4.00 7.28
    Al2O3 1.58 1.58 1.57
    TiO2 20.47 20.54 20.45 20.32
    ZrO2
    Nb2O5
    Sb2O3 0.12 0.09 0.12 0.12
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66844 1.66718 1.67030 1.68131
    ν d 27.63 26.14 26. 84 25.94
    Pg,F 0.630 0.637 0.632 0.634
    Figure imgb0013
    Pg,F
    0.032 0.036 0.033 0.034
    ∑ A2O 22.29 25.85 23.53 22.13
    ∑ EO 6.33 8.43 7.99 11.25
    TiO2/P2O5 0.46 0.46 0.46 0.46
    Al2O3/TiO2 0.08 0.08 0.08
    B2O3/P2O5 0.10 0.03
    TiO2/ (P2O5+B2O3+Al2O3) 0.40 0.46 0.43 0.44
    TiO2/ (TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00 1.00
    (BaO+TiO2)/P2O5 0.54 0.64 0.54 0.54
    (BaO+TiO2+Nb2O5 +Ta2O3+WO3+Bi2O3) / (P2O5+B2O3+SiO2+Al2O3) 0.48 0.64 0.51 0.53
    ∑ A2O/TiO2 1.09 1.26 1.15 1.09
    ∑ EO/ ∑ A2O 0.28 0.33 0.34 0.51
    SiO2+B2O3 4.27 1.42
    [Table 27]
    MASS % EXAMPLE 105 EXAMPLE 106 EXAMPLE 107 EXAMPLE 108
    P2O5 43.78 45.88 44.42 45.61
    SiO2
    B2O3 2.78 2.91 2.82 2.89
    Li2O 1.24
    Na2O 13.77 14.43 13.34 13.70
    K2O 7.33 7.68 11.24 7.63
    MgO
    CaO
    SrO
    BaO 8.48 4.08 3.95 4.05
    ZnO 2.28 2.39 2.31 2.37
    Al2O3 1.54 1.62 1.57 1.61
    TiO2 19.94 20.90 20.23 20.77
    ZrO2
    Nb2O5
    Sb2O3 0.12 0.12 0.12 0.12
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.67654 1.67496 1.66703 1.67910
    νd 27.26 26.70 26.96 26.65
    Pg, F 0.630 0.631 0.633 0.632
    Figure imgb0016
    Pg,F
    0.032 0.032 0.034 0.032
    ∑ A2O 21.09 22.11 24.59 22.57
    ∑ EO 10.75 6.47 6.26 6.43
    TiO2/P2O5 0.46 0.46 0.46 0.46
    Al2O3/TiO2 0.08 0.08 0.08 0.08
    B2O3/P2O5 0.06 0.06 0.06 0.06
    TiO2/(P2O5+B2O3+Al2O3) 0.41 0.41 0.41 0.41
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00 1.00
    (BaO+TiO2)/P2O5 0.65 0.54 0.54 0.54
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.59 0.50 0.50 0.50
    ∑ A2O/TiO2 1.06 1.06 1.22 1.09
    ∑ EO/ ∑A2O 0.51 0.29 0.25 0.28
    SiO2+B2O3 2.78 2.91 2.82 2.89
    [Table 28]
    MASS % EXAMPLE 109 EXAMPLE 110 EXAMPLE 111 EXAMPLE 112
    P2O5 47.29 44.86 31.88 32.05
    SiO2
    B2O3
    Li2O
    Na2O 17.10 18.54 7.96 8.00
    K2O 7.43 7.51 5.34 5.36
    MgO
    CaO
    SrO
    BaO 3.95 6.06 6.09
    ZnO 2.31 4.45
    Al2O3 1.57 1.63 1.64
    TiO2 20.23 24.52 16.71 16.80
    ZrO2
    Nb2O5 5.91
    Sb2O3 0.12 0.12
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3 15.87 3.98
    Bi2O3 14.55 20.17
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.66771 1.69134 1.78560 1.79432
    νd 26.09 24.29 22.76 23.06
    Pg,F 0.636 0.640 0.643 0.636
    Figure imgb0010
    Pg,F
    0.036 0.037 0.037 0.030
    ∑ A2O 24.54 26.05 13.30 13.37
    ∑ EO 6.26 4.45 6.06 6.09
    TiO2/P2O5 0.43 0.55 0.52 0.52
    Al2O3/TiO2 0.08 0.10 0.10
    B2O3/P2O5
    TiO2/(P2O5+B2O3+Al2O3) 0.41 0.55 0.50 0.50
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 1.00 1.00 0.35 0.36
    (BaO+TiO2)/P2O5 0.51 0.55 0.71 0.71
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.49 0.55 1.59 1.57
    ∑ A2O/TiO2 1.21 1.06 0.80 0.80
    ∑ EO/ ∑A2O 0.26 0.17 0.46 0.46
    SiO2+B2O3
    [Table 29]
    MASS % EXAMPLE 113 EXAMPLE 114 EXAMPLE 115 EXAMPLE 116
    P2O5 39.58 43.53 40.33 41.34
    SiO2
    B2O3
    Li2O 1.82 1.69 2.67
    Na2O 15.24 14.21 13.17 15.92
    K2O 6.62 7.28 6.75 3.24
    MgO
    CaO
    SrO
    BaO 3.52
    ZnO 2.06
    Al2O3 1.84 1.92
    TiO2 20.55 28.03 24.45 20.06
    ZrO2
    Nb2O5
    Sb2O3 0.11 0.12 0.11 0.11
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3 10.50 5.02 13.50 14.75
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.70813 1.74456 1.75529 1.71684
    νd 25.27 21.97 22.27 25.21
    Pg,F 0.635 0.649 0.645 0.632
    Figure imgb0014
    Pg,F
    0.033 0.041 0.038 0.030
    ∑ A2O 21.86 23.32 21.61 21.83
    ∑ EO 5.58
    TiO2/P2O5 0.52 0.64 0.61 0.49
    Al2O3/TiO2 0.09 0.10
    B2O3/P2O5
    TiO2/(P2O5+B2O3+Al2O3) 0.50 0.64 0.61 0.46
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.66 0.85 0.64 0.58
    (BaO+TiO2)/P2O5 0.61 0.64 0.61 0.49
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.83 0.76 0.94 0.80
    ∑ A2O/TiO2 1.06 0.83 0.88 1.09
    ∑ EO/ ∑A2O 0.26
    SiO2+B2O3
    [Table 30]
    MASS % EXAMPLE 117 EXAMPLE 118 EXAMPLE 119 EXAMPLE 120
    P2O5 36.67 42.54 40.52 36.93
    SiO2
    B2O3
    Li2O 2.37 1.54
    Na2O 14.12 17.58 16.75 12.06
    K2O 2.87 7.12 6.78 6.18
    MgO
    CaO
    SrO
    BaO
    ZnO 4.22 4.02
    Al2O3 1.70
    TiO2 20.04 23.25 20.03 21.21
    ZrO2
    Nb2O5 4.95
    Sb2O3 0.10 0.11 0.11 0.10
    Ta2O5 9.61
    Y2O3
    La2O3
    Gd2O3
    WO3 1.82
    Bi2O3 22.14 5.19 5.03 12.36
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.74388 1.70204 1.70692 1.76027
    ν d 25.00 24.32 24.75 22.93
    Pg,F 0.628 0.640 0.634 0.639
    Figure imgb0007
    Pg,F
    0.026 0.037 0.031 0.033
    ∑ A2O 19.36 24.70 23.53 19.78
    ∑ EO 4.22 4.02
    TiO2/P2O5 0.55 0.55 0.49 0.57
    Al2O3/TiO2 0.08
    B2O3/P2O5
    TiO2/(P2O5+B2O3+Al2O3) 0.52 0.55 0.49 0.57
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.48 0.82 0.63 0.49
    (BaO+TiO2)/P2O5 0.55 0.55 0.49 0.57
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+Si02+Al2O3) 1.10 0.67 0.79 1.17
    ∑ A2O/TiO2 0.97 1.06 1.17 0.93
    ∑ EO/ ∑ A2O 0.17 0.17
    SiO2+B2O3
    [Table 31]
    MASS % EXAMPLE 121 EXAMPLE 122 EXAMPLE 123 EXAMPLE 124
    P2O5 37.05 42.38 35.68 43.46
    SiO2
    B2O3 3.51
    Li2 O 1.55 1.56 2.77
    Na2O 12.10 14.39 16.50 17.96
    K2O 6.20 6.26 3.36 7.27
    MgO 2.14
    CaO
    SrO
    BaO
    ZnO
    Al2O3 1.99
    TiO2 21.28 30.26 20.79 23.75
    ZrO2
    Nb2O5
    Sb2O3 0.10 0.10 0.11 0.12
    Ta2O5 15.43
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3 6.30 5.05 15.28 5.30
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.75265 1.75884 1.70707 1.69980
    ν d 23.27 21.62 26.91 24.27
    Pg,F 0.634 0.647 0.622 0.637
    Figure imgb0007
    Pg,F
    0.029 0.039 0.023 0.033
    ∑ A2O 19.85 22.21 22.63 25.23
    ∑ EO 2.14
    TiO2/P2O5 0.57 0.71 0.58 0.55
    Al2O3/TiO2 0.10
    B2O3/P2O5 0.10
    TiO2/(P2O5+B2O3+Al2O3) 0.57 0.71 0.50 0.55
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.49 0.86 0.58 0.82
    (BaO+TiO2)/P2O5 0.57 0.71 0.58 0.55
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 1.16 0.83 0.88 0.67
    ∑ A2O/TiO2 0.93 0. 73 1.09 1.06
    ∑ EO/ΣA2O 0.08
    SiO2+B2O3 3.51
    [Table 32]
    MASS % EXAMPLE 125 EXAMPLE 126 EXAMPLE 127 EXAMPLE 128
    P2O5 43.10 42.05 41.38 40.17
    SiO2
    B2O3
    Li2O
    Na2O 17.81 17.38 17.10 16.60
    K2O 7.21 7.04 6.92 6.72
    MgO
    CaO 2.95
    SrO 5.31
    BaO
    ZnO 2.57 2.50
    Al2O3
    TiO2 23.55 22.98 22.61 21.95
    ZrO2
    Nb2O5
    Sb2O3 0.11 0.11 0.11 0.11
    Ta2O5
    Y2O3 4.25
    La2O3
    Gd2O3 6.63
    WO3
    Bi2O3 5.26 5.13 5.05 5.33
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.69772 1.69810 1.69989 1.70469
    ν d 24.80 24.82 25.46 25.30
    Pg,F 0.622 0.636 0.627 0.633
    Figure imgb0006
    Pg,F
    0.019 0.033 0.025 0.031
    ΣA2O 25.03 24.42 24.02 23.32
    ΣEO 2.95 5.31 2.57 2.50
    TiO2/P2O5 0.55 0.55 0.55 0.55
    Al2O3/TiO2
    B2O3/P2O5
    TiO2/(P2O5+B2O3+Al2O3) 0.55 0.55 0.55 0.55
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.82 0.82 0.82 0.80
    (BaO+TiO2)/P2O5 0.55 0.55 0.55 0.55
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.67 0.67 0.67 0.68
    ∑ A2O/TiO2 1.06 1.06 1.06 1.06
    ∑ EO/ ∑A2O 0.12 0.22 0.11 0.11
    SiO2+B2O3
    [Table 33]
    MASS % EXAMPLE 129 EXAMPLE 130 EXAMPLE 131 EXAMPLE 132
    P2O5 42.05 41.97 44.47 43.06
    SiO2 1.15
    B2O3 1.33
    Li2O 1.86
    Na2O 17.38 17.35 19.42 17.80
    K2O 7.04 7.02 7.21
    MgO
    CaO
    SrO
    BaO
    ZnO 4.17 4.16 4.41 2.68
    Al2O3
    TiO2 22.98 22.94 24.30 20.24
    ZrO2
    Nb2O5
    Sb2O3 0.11 0.11 0.12 0.11
    Ta2O5
    Y2O3
    La2O3 3.19
    Gd2O3
    WO3
    Bi2O3 5.13 5.12 5.42 5.71
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.70042 1.69808 1.71941 1.68460
    ν d 24.40 25.01 24.03 25.71
    Pg,F 0.635 0.629 0.637 0.626
    Figure imgb0004
    Pg,F
    0.032 0.027 0.033 0.025
    ∑ A2O 24.41 24.37 21.28 25.00
    ∑ EO 4.17 4.16 4.41 2.68
    TiO2/P2O5 0.55 0.55 0.55 0.47
    Al2O3/TiO2
    B2O3/P2O5 0.03
    TiO2/(P2O5+B2O3+Al2O3) 0.55 0.53 0.55 0.47
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.82 0.82 0.82 0.78
    (BaO+TiO2)/P2O5 0.55 0.55 0.55 0.47
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.65 0.65 0.67 0.60
    ∑ A2O/TiO2 1.06 1.06 0.88 1.24
    ∑ EO/ΣA2O 0.17 0.17 0.21 0.11
    SiO2+B2O3 1.15 1.33
    [Table 34]
    MASS % EXAMPLE 133 EXAMPLE 134 EXAMPLE 135 EXAMPLE 136
    P2O5 42.08 43.51 41.88 24.37
    SiO2 0.76
    B2O3 5.85
    Li2O
    Na2O 17.39 17.31 5.13
    K2O 7.04 19.21 7.01 10.20
    MgO 3.40
    CaO
    SrO
    BaO 14.32
    ZnO 4.18 8.35 4.15
    Al2O3
    TiO2 23.00 20.07 22.88 15.45
    ZrO2 1.06
    Nb2O5 23.86
    Sb2O3 0.11 0.12 0.11 0.06
    Ta2O5
    Y2O3
    La2O3 1.55
    Gd2O3
    WO3
    Bi2O3 5.13 5.35 5.11
    TOTAL 100.00 100.00 100.00 100.00
    nd 1.70538 1.68875 1.70164 1.78593
    νd 24.29 25.66 24.68 23.93
    Pg,F 0.637 0.625 0.634 0.633
    Figure imgb0004
    Pg,F
    0.034 0.023 0.031 0.029
    ∑A2O 24.43 19.21 24.31 15.33
    ∑EO 4.18 11.74 4.15 14.32
    TiO2/P2O5 0.55 0.46 0.55 0.63
    Al2O3/TiO2
    B203/P205 0.24
    TiO2/(P2O5+B2O3+Al2O3) 0.55 0.46 0.55 0.51
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.82 0.79 0.82 0.39
    (BaO+TiO2)/P2O5 0.55 0.46 0.55 1.22
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 0.67 0.58 0.67 1.73
    ΣA2O/TiO2 1.06 0.96 1.06 0.99
    ∑ EO/ ∑ A2O 0.17 0.61 0.17 0.93
    SiO2+B2O3 6.61
    [Table 35]
    MASS % EXAMPLE 137 EXAMPLE 138 EXAMPLE 139
    P2O5 24.37 24.38 35.44
    SiO2 0.76 1.06
    B2O3 5.85 5.55 1.42
    Li2O
    Na2O 4.51 5.13 6.96
    K2O 10.82 10.20 1.01
    MgO
    CaO 1.01 6.29
    SrO
    BaO 13.31 13.82 14.83
    ZnO
    Al2O3
    TiO2 15.45 15.44 25.94
    ZrO2
    Nb2O5 23.86 24.36 8.12
    Sb2O3 0.06 0.06
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.00 100.00
    nd 1.78524 1.78802 1.80663
    νd 24.04 23.76 23.16
    Pg,F 0.633 0.632 0.640
    Figure imgb0004
    Pg,F
    0.029 0.027 0.035
    ∑ A2O 15.33 15.33 7.97
    ∑ EO 14.32 13.82 21.12
    TiO2/P2O5 0.63 0.63 0.73
    Al2O3/TiO2
    B2O3/P2O5 0.24 0.23 0.04
    TiO2/(P2OB+B2O3+Al2O3) 0.51 0.52 0.70
    TiO2/(TiO2+Nb2O5+WO3+ Bi2O3+Ta2O5) 0.39 0.39 0.76
    (BaO+TiO2)/P2O5 1.18 1.20 1.15
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 1.70 1.73 1.33
    ∑ A2O/TiO2 0.99 0.99 0.31
    ∑ EO/ΣA2O 0.93 0.90 2.65
    SiO2+B2O3 6.61 6.61 1.42
    [Table 36]
    MASS % COMPARATIVE EXAMPLE 1 COMPARATIVE EXAMPLE 2 COMPARATIVE EXAMPLE 3
    P2O5 29.59 28.75 28.75
    SiO2
    B2O3
    Li2O 0.39 0.39
    Na2O 8.94 8.69 8.69
    K2O 5.58 5.42 5.42
    MgO
    CaO
    SrO
    BaO 15.70 15.26 15.26
    ZnO
    Al2O3 0.33 0.33
    TiO2 40.12 40.53 40.53
    ZrO2 0.64 0.64
    Nb2O5
    Sb2O3 0.08 0.08
    Ta2O5
    Y2O3
    La2O3
    Gd2O3
    WO3
    Bi2O3
    TOTAL 100.00 100.08 100.00
    nd UNMEASURABLE UNMEASURABLE UNMEASURABLE
    νd UNMEASURABLE UNMEASURABLE UNMEASURABLE
    Pg,F UNMEASURABLE UNMEASURABLE UNMEASURABLE
    Figure imgb0004
    Pg,F
    UNMEASURABLE UNMEASURABLE UNMEASURABLE
    ∑ A2O 14.51 14.49 14.49
    ∑ EO 15.70 15.26 15.26
    TiO2/P2O5 1.36 1.41 1.41
    Al2O3/TiO2 0.01 0.01
    B2O3/P2O5
    TiO2/(P2O5+B2O3+Al2O3) 1.36 1.39 1.39
    TiO2/(TiO2+Nb2O6+WO3+ Bi2O3+Ta2O5) 1.00 1.00 1.00
    (BaO+TiO2)/P2O5 1.89 1.94 1.94
    (BaO+TiO2+Nb2O5 +Ta2O5+WO3+Bi2O3)/ (P2O5+B2O3+SiO2+Al2O3) 1.89 1.92 1.92
    ∑ A2O/TiO2 0.36 0.36 0.36
    ∑ EO/ ∑A2O 1.08 1.05 1.05
    SiO2+B2O3
  • From above, it was confirmed that the optical glasses in Examples were highly dispersive and had a high partial dispersion ratio. Further, it was confirmed that the optical glasses in Examples were excellent in transparency with suppressed coloration.
  • Reference Signs List
    • 1 Imaging device
    • 101 Camera body
    • 102 Lens barrel
    • 103 Lens
    • 104 Sensor chip
    • 105 Glass substrate
    • 106 Multi-chip module
    • CAM Imaging device (fixed lens camera)
    • WL Photographing lens
    • M Liquid crystal monitor
    • EF Auxiliary light emitting unit
    • B1 Release button
    • B2 Function button
    • 2 Multi-photon microscope
    • 201 Pulse laser device
    • 202 Pulse division device
    • 203 Beam adjustment unit
    • 204, 205, 212 Dichroic mirror
    • 206 Objective lens
    • 207, 211, 213 Fluorescence detection unit
    • 208 Condensing lens
    • 209 Pinhole
    • 210 Image forming lens
    • S Sample
    • 3 Cemented lens
    • 301 First lens element
    • 302 Second lens element
    • 303 Joining member

Claims (32)

  1. An optical glass comprising:
    by mass%,
    20% to 55% of a content rate of P2O5;
    10% to 40% of a content rate of TiO2;
    0% to 30% of a content rate of Nb2O5;
    0% to 2% of a content rate of Al2O3;
    0% to 10% of a content rate of B2O3;
    0% to 30% of a content rate of BaO;
    0% to 30% of a content rate of Bi2O3;
    0% to 20% of a content rate of Ta2O5; and
    0% to 25% of a content rate of WO3, wherein
    a ratio of a content rate of TiO2 to a total content rate of P2O5, B2O3, and Al2O3 (TiO2/(P2O5 + B2O3 + Al2O3)) is from 0.25 to 0.85, and
    a ratio of a content rate of TiO2 to a total content rate of TiO2, Nb2O5, WO3, Bi2O3, and Ta2O5 (TiO2/(TiO2 + Nb2O5 + WO3 + Bi2O3 + Ta2O5)) is from 0.25 to 1.00.
  2. The optical glass according to claim 1, wherein
    by mass%,
    a ratio of a total content rate of BaO and TiO2 to a content rate of P2O5 ((BaO + TiO2)/P2O5) is from 0.40 to 1.50.
  3. An optical glass comprising:
    by mass%,
    20% to 55% of a content rate of P2O5;
    10% to 40% of a content rate of TiO2;
    0% to 30% of a content rate of Nb2O5;
    0% to 2% of a content rate of Al2O3;
    0% to 10% of a content rate of B2O3;
    0% to 30°; of a content rate of BaO;
    0% to 30% of a content rate of Bi2O3;
    0% to 20% of a content rate of Ta2O5; and
    0% to 25% of a content rate of WO3, wherein
    a ratio of a total content rate of BaO and TiO2 to a content rate of P2O5 ((BaO + TiO2)/P2O5) is from 0.40 to 1.50.
  4. The optical glass according to claim 3, wherein
    by mass%,
    a ratio of a content rate of TiO2 to a total content rate of P2O5, B2O3, and Al2O3 (TiO2/(P2O5 + B2O3 + Al2O3)) is from 0.25 to 0.85.
  5. The optical glass according to claim 3, wherein
    by mass%,
    a ratio of a content rate of TiO2 to a total content rate of TiO2, Nb2O5, WO3, Bi2O3, and Ta2O5 (TiO2/(TiO2 + Nb2O5 + WO3 + Bi2O3 + Ta2O5)) is from 0.25 to 1.00.
  6. The optical glass according to any one of claims 1 to 5, further comprising:
    by mass%,
    0% to 30% of a content rate of Na2O;
    0% to 25% of a content rate of K2O; and
    0% to 5% of a content rate of Li2O.
  7. The optical glass according to any one of claims 1 to 6, further comprising:
    by mass%,
    0% to 15% of a content rate of ZnO;
    0% to 10% of a content rate of MgO;
    0% to 10% of a content rate of CaO; and
    0% to 15% of a content rate of SrO.
  8. The optical glass according to any one of claims 1 to 7, further comprising:
    by mass%,
    0% to 5% of a content rate of SiO2;
    0% to 5% of a content rate of ZrO2; and
    0% to 1% of a content rate of Sb2O3.
  9. The optical glass according to any one of claims 1 to 8, further comprising:
    by mass%,
    0% to 10% of a total content rate of SiO2 and B2O3.
  10. The optical glass according to any one of claims 1 to 9, further comprising:
    by mass%,
    0% to 8% of a content rate of Y2O3;
    0% to 5% of a content rate of La2O3; and
    0% to 10% of a content rate of Gd2O3.
  11. The optical glass according to any one of claims 1 to 10, further comprising:
    5% to 35° of a total content rate of Li2O, Na2O, and K2O (ΣA2O; where, A = Li, Na, K).
  12. The optical glass according to any one of claims 1 to 11, further comprising:
    0% to 30% of a total content rate of MgO, CaO, SrO, BaO, and ZnO (ZEO; where, E = Mg, Ca, Sr, Ba, Zn).
  13. The optical glass according to any one of claims 1 to 12, wherein
    by mass%,
    a ratio of a content rate of TiO2 to a content rate of P2O5 (TiO2/P2O5) is from 0.25 to 0.85.
  14. The optical glass according to any one of claims 1 to 13, wherein
    a ratio of a content rate of Al2O5 to a content rate of TiO2 (Al2O3/TiO2) is from 0 to 0.15.
  15. The optical glass according to any one of claims 1 to 14, wherein
    a ratio of a content rate of B2O3 to a content rate of P2O5 (B2O3/P2O5) is from 0 to 0.30.
  16. The optical glass according to any one of claims 1 to 15, wherein
    a ratio of a total content rate of BaO, TiO2, Nb2O5, WO3, Bi2O3, and Ta2O5 to a total content rate of P2O5, B2O3, SiO2, and Al2O3 ((BaO + TiO2 + Nb2O5 + WO3 + Bi2O3 + Ta2O5) / (P2O5 + B2O3 + SiO2 + Al2O3)) is from 0.40 to 2.00.
  17. The optical glass according to any one of claims 1 to 16, wherein
    a ratio of a total content rate of Li2O, Na2O, and K2O (ΣA2O; where, A = Li, Na, K) to a content rate of TiO2 (ΣA2O/TiO2) is from 0.10 to 2.00.
  18. The optical glass according to any one of claims 1 to 17, wherein
    a ratio of a total content rate of MgO, CaO, SrO, BaO, and ZnO (ΣEO; where, E = Mg, Ca, Sr, Ba, Zn) to a total content rate of Li2O, Na2O, and K2O (ΣA2O; where, A = Li, Na, K) (ΣEO/ΣA2O) is from 0 to 3.00.
  19. The optical glass according to any one of claims 1 to 18, wherein
    a refractive index (nd) with respect to a d-line falls within a range from 1.60 to 1.85.
  20. The optical glass according to any one of claims 1 to 19, wherein
    an abbe number (νd) falls within a range from 20 to 35.
  21. The optical glass according to any one of claims 1 to 20, wherein
    a partial dispersion ratio (Pg,F) is from 0.61 to 0.66.
  22. The optical glass according to any one of claims 1 to 21, wherein
    abnormal dispersibility (ΔPg,F) is from 0.015 to 0.055.
  23. An optical element using the optical glass according to any one of claims 1 to 22.
  24. An optical system comprising the optical element according to claim 23.
  25. An interchangeable camera lens comprising the optical system according to claim 24.
  26. An objective lens for a microscope comprising the optical system according to claim 24.
  27. An optical device comprising the optical system according to claim 24.
  28. A cemented lens comprising:
    a first lens element; and
    a second lens element, wherein
    at least one of the first lens element and the second lens element comprises the optical glass according to any one of claims 1 to 22.
  29. An optical system comprising the cemented lens according to claim 28.
  30. An objective lens for a microscope comprising the optical system according to claim 29.
  31. An interchangeable camera lens comprising the optical system according to claim 29.
  32. An optical device comprising the optical system according to claim 29.
EP20961572.3A 2020-11-12 2020-11-12 Optical glass, optical element, optical system, cemented lens, interchangable lens for camera, objective lens for microscope, and optical device Pending EP4245736A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2020/042234 WO2022102044A1 (en) 2020-11-12 2020-11-12 Optical glass, optical element, optical system, cemented lens, interchangable lens for camera, objective lens for microscope, and optical device

Publications (1)

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EP4245736A1 true EP4245736A1 (en) 2023-09-20

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EP20961572.3A Pending EP4245736A1 (en) 2020-11-12 2020-11-12 Optical glass, optical element, optical system, cemented lens, interchangable lens for camera, objective lens for microscope, and optical device

Country Status (5)

Country Link
US (1) US20230331623A1 (en)
EP (1) EP4245736A1 (en)
JP (1) JPWO2022102044A1 (en)
CN (1) CN116507594A (en)
WO (1) WO2022102044A1 (en)

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54112915A (en) * 1978-02-24 1979-09-04 Nippon Chemical Ind Optical glass
JPS5969445A (en) * 1982-10-06 1984-04-19 Nippon Kogaku Kk <Nikon> Optical phosphate glass
JP2561835B2 (en) * 1987-04-23 1996-12-11 株式会社 オハラ Optical glass
JP2005053743A (en) * 2003-08-05 2005-03-03 Minolta Co Ltd Optical glass and optical element
JP2012036091A (en) * 2011-11-10 2012-02-23 Ohara Inc Method for producing optical glass
JP6587276B2 (en) * 2013-02-19 2019-10-09 Hoya株式会社 Optical glass, optical glass blank, glass material for press molding, optical element, and production method thereof
JP6927758B2 (en) * 2017-06-14 2021-09-01 光ガラス株式会社 Optical glass, optical elements using it, optical system, lens barrel, objective lens and optical device

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CN116507594A (en) 2023-07-28
WO2022102044A1 (en) 2022-05-19
JPWO2022102044A1 (en) 2022-05-19
US20230331623A1 (en) 2023-10-19

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